01 -
Preheat the oven to 350°F. Line a standard muffin pan with paper liners.
02 -
In a large bowl, whisk together all-purpose flour, baking powder, baking soda, salt, and ground cinnamon until evenly mixed.
03 -
Using a hand mixer or stand mixer, beat softened butter and granulated sugar until light and fluffy. Add eggs one at a time, incorporating fully after each addition. Mix in vanilla extract.
04 -
Alternately add the flour mixture and buttermilk to the creamed butter, beginning and ending with the flour mixture. Mix until just combined. Fold in grated apple gently.
05 -
Divide the batter evenly among prepared liners, filling each about two-thirds full. Bake for 30 to 45 minutes, or until a toothpick inserted into the center comes out clean.
06 -
Remove cupcakes from oven and allow to cool completely on a wire rack before frosting.
07 -
In a medium bowl, beat softened butter until smooth. Gradually add powdered sugar and cinnamon, mixing well. Pour in milk and vanilla extract, beating until the buttercream is creamy and spreadable.
08 -
Once the cupcakes are cool, frost generously with the cinnamon buttercream using a spatula or piping bag.