4ouncesof high-quality dark chocolate,coarsely chopped
1/2cupwhite chocolate chips
1cup(2 sticks) sweet cream butter, softened to room temperature
3 1/2cupspowdered sugar
Preheat oven to 350 degrees F.
In a bowl, whisk egg and sugar until smooth and no lumps remain. Add melted butter and vanilla and mix until combined. Sift dry ingredients together and add to wet mixture. Mix until batter is smooth with a large spoon, then whisk in kahlua. Fold in chocolate. Line a muffin tin with liners and using a heaping 1/4 cup measure, add batter to each cup until 3/4 of the way full. Bake for 15-18 minutes. Let cool completely before frosting.
Beat butter in the bowl of your electric mixer until smooth and creamy, about 2 minutes. Add in powdered sugar gradually (about 1/2 cup at a time) with the mixer on low speed, slowly increasing the speed until it’s combined. Add in vanilla extract and kahlua, then beat on medium-high speed for 3-4 minutes, occasionally scraping down the sides if needed, until white and fluffy. Frost cupcakes and garnish with grated white and dark chocolate.