Heat the canola oil in a large pot over medium-high heat.
Mix the diced apples and lemon juice in a large bowl and set aside.
Whisk the flour, sugar, baking powder, salt, cinnamon, and nutmeg in a separate bowl.
Make a well, add the milk, egg, melted butter, and batter vanilla, and mix just until combined.
Gently fold in the apples until mostly coated.
When the oil reaches 375°F (190°C), measure 1/4 cup batter for each fritter.
Transfer batter to a greased metal spatula and flatten into a medium disc.
Lower the spatula into the oil, releasing the batter; fry only 3 to 4 fritters at a time.
Cook 2 minutes per side until golden brown, then drain on paper towels.
Whisk confectioners sugar, milk or water, glaze vanilla, and cinnamon into a thin glaze.
Dip slightly cooled fritters in the glaze, repeating or drizzling with any extra.