Preheat the oven to 350°F. Line cupcake tins with 24 cupcake liners.
In a small bowl, toss together chocolate chips and ½ tablespoon of flour.
In a large bowl, use an electric mixer to beat together the butter and sugar until light and fluffy (about 5 minutes). Add the eggs, one at a time, beating well after each addition.
Beat in the applesauce and vanilla. Combine the flour, baking powder and salt; add to the creamed mixture alternately with the liqueur, beating well after each addition. Gently stir in the chocolate chips.
Spoon the batter into cupcake liners, filling them about ¾-fulI -I use an ice cream scoop to get the batter neatly into the liners. Bake the cupcakes 18 to 22 minutes, or until the centers of the cupcakes are set.
MAKE THE BUTTERCREAM FROSTING:
Place all ingredients in a large bowl. Use an electric mixer to blend together; mix until smooth and creamy.
Spread on cupcakes with a knife or for a fancier look use a piping bag to swirl on the frosting.