Ingredients
1¾cupscake flour,spooned and leveled
¾tspbaking powder
¼tspbaking soda
¼tspsalt
½cupunsalted butter,softened to room temperature
1cupgranulated sugar
3large egg whites,room temperature
2tsppure vanilla extract
½cupsour cream,full-fat, room temperature
½cupwhole milk,room temperature
½cuprainbow sprinkles,plus extra for garnish
*vanilla buttercream,(see Recipe Notes for recipe), or frosting of choice
Preparation
Preheat the oven to 350 degrees F. Line a 12-cup muffin pan with cupcake liners. Line a second pan with 2 liners. Set aside.
Whisk the cake flour, baking powder, baking soda, and salt together. Set aside.
Using a handheld or stand mixer fitted with a paddle attachment, beat the butter and sugar together on high speed for about 2 minutes until smooth and creamy. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed.
Add the egg whites and vanilla extract. Beat on medium-high speed until combined, then beat in the sour cream. Scrape down the sides and up the bottom of the bowl as needed.
With the mixer on low speed, add the dry ingredients until just incorporated. With the mixer still running on low, slowly pour in the milk until combined. Do not over-mix. Gently and slowly whisk in the sprinkles. The batter will be slightly thick.
Pour or spoon the batter into the liners. Fill only ⅔ full.
Bake for 19 to 22 minutes, or until a toothpick inserted in the center comes out clean. For around 30 mini cupcakes, bake for about 11 to 13 minutes with the same oven temperature.
Allow the cupcakes to cool completely before frosting.
Frost the cooled cupcakes with vanilla buttercream, then serve and enjoy!
