Ingredients

• Nonstick vegetable oil spray
• 6 ounces cream cheese, room temperature
• 1/2 cup smooth old-fashioned peanut butter
• 1/3 cup (packed) golden brown sugar
• 1 large egg
• 2 tablespoons cornstarch
• 1/2 teaspoon vanilla extract
• 6 tablespoons unsalted butter
• 2 ounces semisweet chocolate, chopped
• 2 ounces unsweetened chocolate, chopped
• 2 large eggs
• 1 cup sugar
• 1 teaspoon vanilla extract
• 1/4 teaspoon salt
• 3/4 cup unbleached all purpose flour
• 1/2 cup semisweet chocolate chips

Instructions

1. Preheat oven to 350°F. Spray 8 x 8 x 2-inch baking pan with nonstick spray.
2. Make swirl: Using electric mixer, beat cream cheese and next 5 ingredients in medium bowl until blended and smooth.
3. Using electric mixer, beat cream cheese and next 5 ingredients in medium bowl until blended and smooth.
4. Make brownies: Combine butter and both chopped chocolates in heavy medium saucepan. Stir over low heat until melted and smooth. Remove from heat; cool to room temperature. Whisk in eggs, then sugar, vanilla and salt. Add flour; stir just until blended. Stir in chocolate chips. Spread 1/3 of brownie batter in prepared pan (layer will be thin). Alternate generous tablespoonfuls of remaining brownie batter and peanut swirl batter atop brownie layer in pan. Using small knife, cut through batters, creating marbleized effect; smooth top slightly. Bake brownies until peanut swirl is set and tester inserted into center comes out with moist crumbs attached, about 30 minutes. Cool in pan on rack.
5. Combine butter and both chopped chocolates in heavy medium saucepan. Stir over low heat until melted and smooth. Remove from heat; cool to room temperature. Whisk in eggs, then sugar, vanilla and salt. Add flour; stir just until blended. Stir in chocolate chips.
6. Spread 1/3 of brownie batter in prepared pan (layer will be thin). Alternate generous tablespoonfuls of remaining brownie batter and peanut swirl batter atop brownie layer in pan. Using small knife, cut through batters, creating marbleized effect; smooth top slightly.
7. Bake brownies until peanut swirl is set and tester inserted into center comes out with moist crumbs attached, about 30 minutes. Cool in pan on rack.