I used Betty Crocker Original Supreme Brownie mix.
1 package (8 ounces) cream cheese, softened
1/2 cup granulated sugar
2 tablespoons unsalted butter, softened
2 large eggs, at room temperature
3 tablespoons heavy cream or whole milk
1 tablespoon all-purpose flour
1 teaspoon vanilla extract
1/2 bar (.75 ounces) semisweet chocolate, chopped
Preheat oven to 325°F. Line an 8-inch square baking pan with aluminum foil and spray foil with nonstick cooking spray.
Prepare brownie mix as directed on box. Spread batter in prepared pan.
Beat cream cheese, sugar and butter in large bowl until creamy and smooth, using electric mixer at medium speed. Add eggs, cream and flour, beating just until combined. Add the vanilla extract. Pour cheesecake mixture over the chocolate layer.
Place chocolate in microwave-safe cup. Microwave in 20 second intervals until melted, stirring between each.
Drizzle melted chocolate over the cheesecake layer. Drop pan on counter to burst any air bubbles in the cheesecake layer.
Bake for 35 to 40 minutes or until the cheesecake layer is set. Cool completely on a wire rack. Then chill several hours or overnight before cutting into 2-inch squares.