For Cupcakes:
3/4 cup strong hot coffee
3 tsp instant espresso powder
3/4 cup dark cocoa
3/4 cup unsalted butter, room temperature
2 cups brown sugar
3 large eggs, room temperature
2 1/2 cups flour
1 cup buttermilk, room temperature
1 tsp baking soda
1 tsp baking powder
1 tsp kosher salt
1 tsp vanilla extract
2 tbsp mayonnaise, room temperature

For frosting:
5 egg whites
1 cup + 2 tbsp sugar
2 cups of unsalted butter at room temperature
1 tsp pure vanilla
pinch of salt
Bailey’s to taste