- Nonstick vegetable oil spray
- 8 ounces bittersweet chocolate, finely chopped
- 1/2 cup (1 stick) unsalted butter, diced
- 1/2 cup sugar
- 2 large eggs
- 1 teaspoon vanilla extract
- 1/2 cup all purpose flour
- 1/4 teaspoon salt
- 1 8-ounce package cream cheese, room temperature
- 1/3 cup creamy (smooth) natural peanut butter (made with only peanuts and salt)
- 1 teaspoon vanilla extract
- 1/2 cup sugar
- 2 large eggs
- 2 tablespoons heavy whipping cream
- 2 tablespoons all purpose flour
- 2 ounces bittersweet chocolate, chopped
- Position rack in center of oven and preheat to 325°F. Spray 9-inch square metal baking pan with 2-inch-high sides with nonstick spray; line bottom with parchment paper.
- Stir chocolate and butter in medium saucepan over low heat until smooth; cool 10 minutes. Using electric mixer, beat sugar, eggs, and vanilla in medium bowl until very fluffy, about 3 minutes. Beat in chocolate mixture on low speed, then beat in flour and salt. Spread batter in pan.
- Using electric mixer, beat cream cheese, peanut butter, and vanilla in medium bowl until smooth. Gradually add sugar, beating until fluffy. Beat in eggs 1 at a time. Beat in cream, then flour. Transfer 1/3 cup cheesecake batter to small bowl and reserve. Spread remaining cheesecake batter over brownie layer.
- Place chocolate in small microwave-safe bowl. Microwave on low power in 10-second intervals until chocolate begins to melt, then stir until smooth. Mix chocolate into reserved 1/3 cup cheesecake batter. Drop chocolate batter by heaping teaspoonfuls atop cheesecake layer. Using chopstick or wooden skewer, swirl chocolate batter in figure-eight pattern through white cheesecake layer.
- Bake brownies until edges of cheesecake layer are puffed and center is set, about 36 minutes. Cool brownies in pan on rack. Cover; chill at least 1 hour.
- Cut brownies into 25 squares. Using narrow spatula, transfer brownies to platter. Serve cold.