For brownie batter:
- 1 stick unsalted butter (8 tablespoons), cut into pieces
- 4 ounces unsweetened chocolate, chopped
- 1 cup sugar
- 2 large eggs
- 3/4 teaspoon pure vanilla extract
- 2/3 cup all-purpose flour
- 1/2 teaspoon salt
For cheesecake batter:
- 8 ounces cream cheese, softened
- 1/3 cup sugar
- 1 large egg yolk
- 1/4 teaspoon pure vanilla extract
- 1/4 teaspoon salt
Pre-heat the oven to 350°F. Line an 8-inch square baking pan with foil and spray with cooking spray.
To make the brownie batter, melt the butter and chocolate in in the microwave in a medium size microwave safe bowl, stirring occasionally and keeping a close eye, until melted. Stir until completely smooth. Beat in the sugar, eggs, vanilla and salt with an electric beater until well combined. Add the flour and stir with a rubber spatula until just combined. Spread in a baking pan.
To make the cheesecake batter, beat the cheesecake batter ingredients with an electric mixer until smooth. Dollop over the brownie batter, then swirl in with a knife or spatula.
Bake until edges are slightly puffed and center is just set, about 30-35 minutes. Let cool completely, then chill in the refrigerator for at least an hour. When ready to serve, remove the foil and bars from the pan and cut into even squares. Serve chilled or at room temperature.