For the cupcakes:
2 cups all-purpose flour
1 teaspoon baking powder
¼ teaspoon baking soda
¼ teaspoon salt
½ cup boiling water
2 tablespoons instant-espresso powder
¼ cup whole milk
½ cup (8 tablespoons) unsalted butter, room temperature
½ cup granulated sugar
½ cup packed light-brown sugar
2 large eggs
For the frosting:
1 cup heavy cream
1 tablespoon confectioners’ sugar
1 tablespoon whiskey
Instant-espresso powder, for dusting
Heat oven to 350º and line two cupcake tins with paper cups.
To make the cupcakes, whisk the flour, baking powder, baking soda and salt together in a Make the cupcakes: Whisk together flour, baking powder, baking soda, and salt in a medium bowl. Combine the water and espresso powder and set aside to cool slightly, then pour into the milk.
In the bowl of an electric mixer fitted with a paddle attachment, beat the butter and sugars on medium for about 3 minutes, until pale and fluffy. Add eggs, 1 at a time, beating well after each addition. Beat the flour mixture in 3 additions, alternating with the milk, beginning and ending with the flour.
Fill the cups about ¾ full and bake for 20-22 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool slightly in the pans, and then transfer to a wire rack to cool completely.
While the cupcakes are cooling, make the frosting. Use an electric mixer to whip the cream and sugar until medium peaks form. Add the whiskey and continue whisking until slightly stiffer peaks form. Top each cupcake with the frosting and then dust with espresso powder.