Peanut Butter Sheet Cake

There are some recipes that just feel like a warm hug, aren’t there? For me, that’s absolutely the Peanut Butter Sheet Cake. It’s not just a dessert; it’s memory. I remember my mom making this for after-school treats when I was a kid. The entire house would fill with the most incredible aroma of roasted peanuts and sweet batter, and it was my signal that a good afternoon was about to get even better. This peanut butter sheet cake is the kind of thing that disappears in minutes at my house, and honestly, it’s a lifesaver on busy nights when I need something sweet but don’t have time for a fussy layer cake. It’s way easier than you might think, and the flavor… oh, the flavor! It’s rich, it’s decadent, and it’s pure peanut butter bliss. If you’re a fan of classic chocolate chip cookies or fudgy brownies, you’re going to fall head over heels for this simple, yet spectacular, peanut butter sheet cake.

What is a peanut butter sheet cake?

So, what exactly is Peanut Butter sheet cake? Think of it as the easiest, most delicious way to get your peanut butter fix. It’s essentially a moist, tender cake baked in a rectangular pan (a “sheet” pan, hence the name!), topped with a luscious peanut butter frosting or glaze. It skips all the fuss of leveling, torting, and stacking layers, making it incredibly approachable for bakers of all levels. This isn’t a fancy, intimidating dessert. It’s down-to-earth, crowd-pleasing comfort food in cake form. The batter itself is infused with that unmistakable peanut butter flavor, and the topping just takes it to a whole new level of deliciousness. It’s the kind of cake you can whip up for a last-minute potluck, a birthday celebration, or just because you’re craving something truly satisfying. It’s honest, straightforward, and utterly delightful.

Why you’ll love this recipe?

There are so many reasons why this Peanut Butter sheet cake has become a staple in my kitchen, and I just know you’re going to love it too! First and foremost, the FLAVOR. If you’re a peanut butter lover, prepare yourself. It’s intensely peanut buttery, with a perfect balance of sweet and salty that just sings. The cake itself is unbelievably moist and tender – no dry crumbly bits here! And the frosting… oh my goodness, the frosting! It’s creamy, rich, and has just the right amount of peanut butter punch.

Then there’s the SIMPLICITY. Seriously, this recipe is a dream. You mix up a batter in one bowl, pour it into a pan, bake, and then whip up a quick frosting while it cools. It’s so forgiving! I’ve honestly messed up a step or two in the past (who hasn’t?), and it still turned out wonderfully. It’s the perfect recipe for when you’re short on time but still want to impress. And speaking of impressing, this cake is incredibly COST-EFFECTIVE. The ingredients are all pantry staples – flour, sugar, eggs, butter, milk, and, of course, Peanut Butter. You likely have most of them on hand right now!

VERSATILITY is another huge plus. While I love it with the classic Peanut Butter frosting, you can totally switch it up. A simple powdered sugar glaze is lovely, or you could drizzle it with melted chocolate for an extra indulgence. It’s also amazing served warm or at room temperature. What I love most about this peanut butter sheet cake, though, is how it brings people together. It’s the kind of dessert that sparks conversations and happy memories. It reminds me of my grandmother’s kitchen and simpler times. It’s just pure, unadulterated joy in cake form. It’s also a fantastic alternative to those elaborate frosted layer cakes when you want that wow factor without all the effort.

How do I make a peanut butter sheet cake?

Quick Overview

This peanut butter sheet cake is all about ease and incredible flavor. You’ll simply whisk together your dry and wet ingredients in separate bowls, then combine them into a wonderfully moist batter. The magic happens when you pour it into your prepared sheet pan and bake until golden. While it cools, you’ll whip up a dreamy peanut butter frosting that you’ll spread all over the top. It’s a straightforward process that yields a show-stopping dessert with minimal fuss, perfect for any occasion or just a Tuesday night treat!

Ingredients

For the Main Batter:

2 cups all-purpose flour: Make sure it’s fresh! Sift it if you want an extra tender cake, though I often skip this step and it’s still fantastic.

1 ½ cups granulated sugar: This gives the cake its sweetness and helps with tenderness.

1 teaspoon baking soda: Our leavening agent, essential for a good rise.

½ teaspoon salt: Balances the sweetness and enhances the peanut butter flavor.

½ cup (1 stick) unsalted butter, softened: Using softened butter ensures it creams nicely with the sugar for a tender crumb.

½ cup creamy peanut butter: Use your favorite brand! Natural peanut butter can sometimes separate, so a standard creamy one works best here for consistency.

2 large eggs: At room temperature, they incorporate better.

1 teaspoon vanilla extract: A classic flavor enhancer.

1 cup buttermilk: This is the secret to a super moist cake! If you don’t have any, you can make a quick substitute by adding 1 tablespoon of white vinegar or lemon juice to 1 cup of milk and letting it sit for 5-10 minutes.

For the Glaze (optional, but highly recommended!):

½ cup creamy peanut butter: Again, your favorite brand works wonders.

⅓ cup unsalted butter, melted: This creates a smooth, rich glaze.

1 teaspoon vanilla extract: For that extra touch of flavor.

2 cups powdered sugar, sifted: Sifting prevents lumps and ensures a smooth glaze. You might need a little more or less depending on your desired consistency.

2-4 tablespoons milk (or half-and-half): To thin the glaze to your liking.

Step-by-Step Instructions

Step 1: Preheat & Prep Pan

First things first, let’s get that oven preheated to 350 degrees F (175 degrees C). While it’s heating up, grab a 9×13 inch baking pan. I like to grease mine really well with butter or cooking spray, and then give it a light dusting of flour. You can also line it with parchment paper, leaving some overhang on the sides to make lifting the cake out easier later. This step is crucial to prevent sticking and ensure your beautiful peanut butter sheet cake comes out in one perfect piece.

Step 2: Mix Dry Ingredients

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking soda, and salt. Give it a good whisk until everything is evenly combined. This ensures the leavening agent and salt are distributed throughout, leading to a uniform rise and flavor. Don’t skip this – it’s a simple step that makes a difference!

Step 3: Mix Wet Ingredients

In a separate medium bowl, cream together the softened unsalted butter and the ½ cup of creamy peanut butter until they are smooth and well combined. This is where that lovely peanut butter flavor really starts to shine! Then, beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the vanilla extract. Finally, gradually add the buttermilk, mixing until just combined. It might look a little separated, but don’t worry, it will come together.

Step 4: Combine

Now for the best part: bringing it all together! Pour the wet ingredients into the bowl with the dry ingredients. Mix on low speed (or gently with a spatula) until just combined. Be super careful not to overmix! Overmixing can develop the gluten in the flour too much, resulting in a tougher cake. Stop as soon as you don’t see any dry streaks of flour. A few small lumps are perfectly fine.

Step 5: Prepare Filling

Wait until your cake is almost done baking to prepare the glaze. In a medium bowl, combine the ½ cup of creamy peanut butter and the melted unsalted butter. Stir until smooth. Then, stir in the vanilla extract. Gradually add the sifted powdered sugar, mixing until combined. It will be quite thick at this point. Add the milk (or half-and-half) one tablespoon at a time, stirring after each addition, until you reach your desired glaze consistency. You want it pourable but not too thin. Test it – it should coat the back of a spoon beautifully!

Step 6: Layer & Swirl

Gently pour or spread the cake batter evenly into your prepared 9×13 inch baking pan. Try to get it as level as possible, but don’t stress too much about perfection. The goal is a beautiful, rustic cake that’s irresistible. There’s no ‘swirling’ needed for the cake batter itself in this recipe; it’s a straightforward pour and bake.

Step 7: Bake

Pop the pan into your preheated oven. Bake for 30-35 minutes, or until a wooden skewer or toothpick inserted into the center of the cake comes out clean. Keep an eye on it, as oven temperatures can vary! If the top starts to brown too quickly, you can loosely tent it with foil. The aroma that fills your kitchen during this time is pure magic – a sweet, nutty cloud that will have everyone asking, “What’s baking?”

Step 8: Cool & Glaze

Once the cake is baked, remove it from the oven and let it cool in the pan on a wire rack for at least 15-20 minutes. This is crucial! Trying to glaze a piping hot cake will result in a melted mess. You want it mostly cooled but still a little warm. Once it’s at that perfect temperature, pour or spread your prepared peanut butter glaze evenly over the top. The residual warmth of the cake will help it smooth out beautifully. If you prefer a thicker glaze, let the cake cool completely before applying.

Step 9: Slice & Serve

Allow the glaze to set for a bit, about 10-15 minutes, before slicing. I find the easiest way to get clean cuts is to use a sharp knife that’s been dipped in hot water and dried. Cut into squares or rectangles – whatever size your heart desires! This cake is fantastic served slightly warm with the glaze still a little soft, or at room temperature. It’s simple, elegant in its own way, and utterly delicious.

What to Serve It With

This peanut butter sheet cake is so versatile, it’s a go-to for so many occasions!

For Breakfast: Yep, you heard me! A small slice of this is surprisingly delightful with a cup of hot coffee. The richness of the cake is balanced by the bitterness of the coffee, making for a decadent start to your day. I sometimes cut it into smaller, bite-sized pieces and serve them on a platter alongside fruit salad for a sweet breakfast treat.

For Brunch: This cake really shines at brunch. It’s easy to make ahead, so you can focus on other dishes. I love to serve it alongside fresh berries – the tartness of the raspberries or strawberries cuts through the sweetness of the cake beautifully. A dollop of whipped cream or a scoop of vanilla bean ice cream takes it over the top.

As Dessert: This is its most obvious role, and it plays it perfectly! For a more elegant dessert, I’ll sometimes add a drizzle of dark chocolate ganache over the peanut butter glaze. It’s also wonderful with a glass of milk (especially for the kids!) or a dessert wine for the grown-ups.

For Cozy Snacks: This is where this cake truly lives in my heart. On a chilly afternoon, curled up with a good book and a warm mug of tea, a slice of this peanut butter sheet cake is pure comfort. My family devours it as an afternoon snack, often asking for seconds! It’s the perfect companion to a lazy weekend afternoon or a busy weeknight when you need a little pick-me-up.

Top Tips for Perfecting Your Peanut Butter Sheet Cake

I’ve made this peanut butter sheet cake more times than I can count, and along the way, I’ve picked up a few tricks that I think really make a difference.

Zucchini Prep: Wait, zucchini? Oh, my apologies! I must have gotten my recipes mixed up in my head for a second there! This is a peanut butter cake, not a zucchini bread. No zucchini involved, which makes it even easier, right? My brain was clearly in overdrive thinking about all the deliciousness!

Mixing Advice: The absolute biggest tip I can give you is this: DO NOT OVERMIX the batter. Once you combine the wet and dry ingredients, mix until they are *just* combined. A few little lumps are perfectly fine. Overmixing develops the gluten in the flour, which can lead to a tough, dense cake. I learned this the hard way early on, and now I’m super mindful about it. Use a spatula and fold gently, or use your mixer on the lowest speed just until streaks of flour disappear.

Swirl Customization: There’s no swirling in the cake batter itself, but for the glaze, you can have some fun! If you want a slightly different look, you can drizzle melted chocolate over the peanut butter glaze and then use a toothpick to gently swirl it. It looks fancy, but it’s so simple! Just make sure your peanut butter glaze has set up slightly before drizzling the chocolate, otherwise, it will all just blend together too much.

Ingredient Swaps: While this recipe is wonderful as is, I have experimented a bit! For the buttermilk, if you’re in a pinch, using regular milk with a tablespoon of white vinegar or lemon juice added and let to sit for 5 minutes works as a great substitute. I’ve also tried using a mix of smooth and crunchy peanut butter in the glaze, and it adds a nice textural element. For the flour, I haven’t personally tested a gluten-free version extensively, but I would recommend a good quality gluten-free all-purpose flour blend that contains xanthan gum. You might need to adjust the liquid slightly.

Baking Tips: Always preheat your oven properly. An oven thermometer is a great investment if you’re unsure about your oven’s accuracy. Bake the cake on the center rack to ensure even cooking. If the top is browning too quickly before the center is cooked, loosely tent the pan with aluminum foil. The toothpick test is your best friend here – it should come out with moist crumbs attached, not wet batter.

Glaze Variations: The glaze is so simple, but you can really play with it! If you want a less sweet glaze, try reducing the powdered sugar slightly and adding a pinch more salt. For a deeper peanut butter flavor, you can use a slightly darker roast peanut butter, but be aware this can sometimes affect the color and texture. If you’re not a huge fan of peanut butter frosting, a simple dusting of powdered sugar or a chocolate ganache are also fantastic options!

Storing and Reheating Tips

One of the best things about this peanut butter sheet cake is how well it stores. It’s so convenient!

Room Temperature: This cake is usually best enjoyed within 1-2 days. Keep it at room temperature, loosely covered with plastic wrap or a cake dome. Make sure the glaze has set a bit before covering. If it’s very warm in your kitchen, it’s safer to refrigerate it, but I find it has the best texture at room temp.

Refrigerator Storage: If you need to store it for longer, definitely use the refrigerator. Place the cooled cake in an airtight container. It will stay fresh and delicious for up to 4-5 days. The glaze will firm up nicely in the fridge. When you’re ready to serve it from the fridge, I highly recommend letting it sit out for about 20-30 minutes to take the chill off and soften the texture a bit. It makes a world of difference!

Freezer Instructions: Yes, you can freeze this cake! Let the cake cool completely, and allow the glaze to set firm. Then, wrap the entire pan tightly with plastic wrap, followed by a layer of aluminum foil. You can also cut it into individual portions and wrap those tightly. It should keep well in the freezer for up to 2-3 months. To thaw, remove it from the freezer and let it defrost in the refrigerator overnight. If you froze individual slices, you can let them thaw at room temperature for a bit.

Glaze Timing Advice: If you plan to freeze the cake, it’s often best to glaze it *after* thawing. This helps prevent the glaze from cracking or becoming too hard during the freezing process. If you’re just refrigerating it, glazing before storing is perfectly fine. For room temperature storage, ensure the glaze is set before covering to avoid it sticking to the wrap.

Frequently Asked Questions

Final Thoughts

So there you have it – my go-to, fail-proof recipe for the most incredible peanut butter sheet cake. It’s more than just a recipe; it’s a little slice of happiness that’s perfect for any occasion, or no occasion at all! The combination of that tender, moist cake and the luscious peanut butter glaze is simply divine. It’s proof that you don’t need fancy techniques or complicated ingredients to create something truly spectacular.

If you love this peanut butter sheet cake, you might also enjoy my recipes for [link to similar recipe, e.g., Fudgy Chocolate Brownies] or my [link to another similar recipe, e.g., Easy Vanilla Cupcakes]. They’re all about bringing joy to your kitchen with delicious, approachable recipes.

I really hope you give this peanut butter sheet cake a try. It’s a recipe that’s brought so much joy to my family and friends, and I’m sure it will do the same for you. I can’t wait to hear how yours turns out in the comments below! Don’t forget to share your photos if you make it – I’d absolutely love to see them!

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Peanut Butter Sheet Cake

A decadent and easy peanut butter sheet cake, perfect for any occasion. This moist cake is topped with a creamy peanut butter frosting.

Prep : 10 Total : 25 minutes

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Ingredients

  

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Cake

• 2.5 cups all-purpose flour
• 2 cups granulated sugar
• 1.5 teaspoons baking soda
• 1 teaspoons salt
• 1 cup unsalted butter, softened
• 0.5 cup creamy peanut butter
• 2 large eggs
• 1 teaspoon vanilla extract
• 1 cup buttermilk

Peanut Butter Frosting

• 0.5 cup unsalted butter, softened
• 0.5 cup creamy peanut butter
• 4 cups powdered sugar
• 0.33 cup milk
• 1 teaspoon vanilla extract

Instructions

 

Make the Cake

• Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
• In a large bowl, whisk together the flour, sugar, baking soda, and salt.
• In a separate bowl, cream together the softened butter and peanut butter until smooth.
• Beat in the eggs one at a time, then stir in the vanilla extract.
• Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined.
• Pour the batter into the prepared baking pan and spread evenly.
• Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
• Let the cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely.

Make the Frosting

• In a medium bowl, beat together the softened butter and peanut butter until smooth and creamy.
• Gradually add the powdered sugar, alternating with the milk, until the frosting reaches your desired consistency. Beat in the vanilla extract.

Assemble

• Once the cake is completely cooled, spread the peanut butter frosting evenly over the top.
• Slice and serve.

Notes

Store any leftover cake in an airtight container at room temperature for up to 3 days.