For the brownie batter:
- 1/2 cup unsalted butter
- 1 cup semisweet chocolate chips
- 1 cup dark chocolate chips
- 1 cup all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon salt
- 4 large eggs
- 1 1/2 cups granulated sugar
- 2 teaspoons vanilla extract
- 2 tablespoon bourbon
For the peanut butter mixture:
- 1 cup smooth peanut butter
- 7 tbsp melted butter
- 1/2 tsp vanilla
- 3 tbsp bourbon
- 1/2 cup powdered sugar