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
- Preheat the oven to 350 degrees.
- Butter 12-by-9 baking dish and line the bottom and sides with a baking sheet.
- Make the peanut butter mixture. Using a spatula and a medium bowl, mix the melted butter, powdered sugar, vanilla, and bourbon until smooth and there are no lumps. Set aside.
- Next, make the chocolate batter. Start by melting the chocolate and butter in a heatproof bowl above a pot of simmering water. Once melted remove from heat.
- In a medium bowl mix together the flour, baking powder, and salt. Set aside.
- In a large bowl with an electric mixer mix together the eggs and sugar on medium speed until slightly thickened. Next, slowly add the dry ingredients mixing until just combined. Stir in the melted chocolate, bourbon and vanilla.
- Pour the chocolate batter into the prepared baking dish and spread it until it's flat and even.
- Using a spoon dot the peanut butter mixture over the brownie batter, then using a knife lightly swirl the peanut butter into the batter until a pretty marble effect is reached.
- Bake for 40-50 minutes or until the batter is set.