Cupcakes:

1. Preheat your oven to 350°F (175°C).
2. Line a muffin tin with paper liners.
3. In a medium bowl, beat the butter and sugar until creamy.
4. Add eggs one at a time, then mix in the vanilla.
5. In another bowl, whisk flour, cocoa powder, and baking powder together. Slowly add this to the wet mixture.
6. Stir in the milk until the batter is smooth, but don’t overmix.
7. Spoon into muffin cups, filling each about ¾ full.
8. Bake for 22–25 minutes, or until a toothpick comes out clean.
9. Let cool completely before frosting.

Buttercream:

1. In a large mixing bowl, whisk together sugar, egg whites, and vanilla until combined.
2. Beat on high for 8 minutes.
3. The mixture will look a little glossy and thick, but not fluffy; that’s normal.
4. Reduce to low speed and add butter in small chunks. It may look curdled or runny at first, but keep going.
5. Once all the butter is in, crank the speed back to high and beat another 8 minutes until smooth and creamy.
6. Chill slightly before frosting for the best texture.

Tip: Frost only when cupcakes are fully cooled.