Instructions

1. For the cake, whisk together the egg whites, and ¼ cup of the milk in small bowl until slightly combined. Set aside.
2. In mixing bowl, beat butter and sugar for 2 minutes on medium. Add in dry ingredients and mix until combined. Slowly in a steady stream add in the egg white mixture. Beat in remaining milk and melted white chocolate bar.
3. Fill cupcake liners half full with batter and bake in a 350 degree oven for about 15 minutes. Remove and cool in pan 5 minutes then transfer to a wire rack. Cool completely before frosting.
4. For the frosting, beat butter 5 minutes until it becomes pale in color. Add sugar, melted white chocolate and whole milk. Beat an additional 5 minutes until fluffy. Fill a disposable pastry bag with frosting (no tip on the end). Set aside.
5. For PB frosing, beat butter 5 minutes until pale in color. Add sugar, peanut butter and whole milk. Beat an additional 3-5 minutes until fluffy. Fill a disposable pastry bag with frosting (no tip on end).
6. Take a LARGE pastry bag and add both types of frosting, making sure the ends of each bag go down to the bottom. Using a 6S tip, pipe onto cupcakes. The peanut butter frosting is very light, so it's hard to see the swirl. That's okay, you will taste it!!