For the cupcakes
1 cups boiling water
1/2 cup unsweetened cocoa powder
1 1/2 cups all-purpose flour
1 teaspoons baking soda
1/2 teaspoon baking powder
1/2 teaspoon salt
1/2 cup butter, softened
1 cup granulated sugar
2 teaspoon vanilla extract
2 tablespoons espresso powder
For the frosting
3 egg whites
1/2 pound unsalted butter, room temperature cut into pieces
3/4 cup granulated sugar
2 teaspoons of pure vanilla extract
6 tablespoon caramel or butterscotch ice cream topping
Preheat oven to 350F. Line a muffin pan with cupcake liners.
Combine vanilla and espresso powder until dissolved; set aside.
In medium bowl, pour boiling water over cocoa, and whisk until smooth. Let mixture cool. Sift together flour, baking soda, baking powder and salt; set aside. In the bowl of a stand mixer, cream butter and sugar together until light and fluffy. Beat in eggs one at time, then stir in vanilla and espresso powder. Add the flour mixture alternately with the cocoa mixture, ending with the flour.
Fill the lined muffin cups three-quarters full, being careful not to overfill. Bake until a toothpick inserted in the center of the cupcake comes out clean, about 18 to 20 minutes. Cool the cupcakes in the pan for 10 minutes, then transfer to a wire rack to cool completely.
To make the frosting, whisk egg whites and sugar in a glass or stainless steel bowl over a pot of boiling water (or a double boiler), making sure the bottom of the bowl is not touching the water. Whisk until the egg whites feel warm to touch (110F) and no grain of sugar can be felt. Pour egg mixture to a stand mixer bowl. Using the whisk attachment, beat on high until about room temperature. When meringue is nice and fluffy, throw in pieces of butter a little at a time. Refrigerate frosting for a minimum of 20 minutes before frosting your cupcakes.
Drizzle with caramel sauce and refrigerate again for at least an hour before serving.