Preparation Steps

• Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
• In a bowl, mix the flour, cocoa powder, baking soda, and salt.
• In a separate bowl, cream together the butter and sugar until light and fluffy. Add in the vanilla extract and egg, and beat well.
• Gradually add the dry ingredients to the wet ingredients and mix until just combined. Fold in the mini marshmallows.
• Drop tablespoons of dough onto the prepared baking sheet, leaving enough space for spreading.
• Bake for 8-10 minutes, or until the cookies are set around the edges.
• Let the cookies cool on the baking sheet for a few minutes, then transfer to a wire rack to cool completely.