Chocolate Truffle Cupcakes

1/2 cup butter
3/4 cup sugar
2 eggs
6 1/2 ounces bittersweet chocolate, melted
2 cups self-rising flour
2 tablespoons unswetened cocoa powder
1 teaspoon baking powder
1 cup milk
12 hershey kisses

Preheat the oven to 400ºF. Lightly grease a 12-cup capacity muffin pan. Cream the butter and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition. Stir in the chocolate, flour, cocoa powder, and baking powder alternately with the milk. Spoon the mixture into the prepared pans and top each cake with a chocolate button. Bake for 20 minutes, or until cooked and a skewer inserted in the middle of one of the cakes comes out clean. Turn the cupcakes out onto a wire rack to cool completely. Serve warm or cool with freshly brewed coffee.