Cheesecake Marbled Brownies
1 stick unsalted butter, cut into pieces
2 ounces unsweetened chocolate, chopped
1 cup sugar
2 large eggs
1/2 teaspoon pure vanilla extract
2/3 cup all purpose flour
8 ounces cream cheese, well softened
1/3 cup sugar
1 large egg yolk
1/4 teaspoon pure vanilla extract
Make brownie batter: Put oven rack in the middle position and preheat oven to 350 degrees. Butter an 8" square baking pan.
Heat butter and chocolate in a 3 quart heavy saucepan over moderately low heat, whisking occasionally, just until melted. Remove from heat and whisk in sugar, eggs, vanilla, and pinch of salt until well combined. Whisk in flour until just combined and spread in baking pan.
Make cheesecake batter and bake brownies: Whisk together cheesecake batter ingredients in a small bowl until smooth. Dolloop over brownie batter, then swirl in with a knife or spatula. Bake until edges are slightly puffed and cenber is just set, about 35 minutes. Serve warm or at room temperature.