Preheat oven to 350F and fill a cupcake tin with liners. Set aside.
Whisk together the cake flour, baking soda, baking powder, salt, and milk powder. Set aside.
192 grams cake flour, ½ teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon fine sea salt, 1 tablespoon milk powder
Separately, beat together the unsalted butter, oil, and sugar until combined & fluffy.
57 grams unsalted butter, 50 grams vegetable oil, 150 grams granulated sugar
Add the eggs & vanilla and mix well, then add the dry ingredients and beat until almost combined.
2 eggs, 1 tablespoon vanilla bean paste or vanilla extract
Once almost mixed in, add the sour cream and mix until almost combined. Then, stream in the milk & beat until a smooth batter forms.
80 grams whole milk, 120 grams sour cream or yogurt
Fill each cupcake liner about half way. Bake for 15 minutes until risen and fluffy - a toothpick inserted into the center should come out clean or with a few moist crumbs.
While the cupcakes cool, make the buttercream. Beat the butter on medium-high speed until creamy. Add the powdered sugar, cocoa, salt, vanilla, & milk, and beat on low speed for 30 seconds, then increase to high speed and beat until combined and smooth.
226 grams unsalted butter, 420 grams powdered sugar, 40 grams dutch processed cocoa powder, pinch of salt, 2 teaspoons vanilla extract, 3-4 tablespoons milk/heavy cream
Once the cupcakes have cooled completely, frost with a piping bag or by hand, top with sprinkles, and enjoy!
sprinkles