Whisk together softened cream cheese, sour cream, 2 tablespoons granulated sugar and 1 tablespoon all-purpose flour. Set aside.

Preheat oven to 325 degrees F with the baking rack in the center of the oven. Cut parchment paper to 8” x 12”. Line an 8” square baking dish with the measured parchment paper (or foil) to act as a sling to remove the brownies. Spray with nonstick cooking spray.

In a medium bowl, combine flour, baking powder and salt. Set aside.

In a microwavable glass dish, microwave chocolate and butter together until melted, stirring at 20 second intervals. Set aside to cool.

In another medium bowl, combine sugar,  eggs and vanilla until well mixed. Stir in melted chocolate until incorporated. Add flour mixture and stir just to combine.

Transfer ½ cup of the brownie batter to a bowl (like the one used to melt the chocolate) and set aside. Spread remaining brownie batter in the prepared pan. Gently spread cream cheese mixture over the brownie batter.

Stir reserved brownie batter (or microwave for a few seconds if needed) and spoon dollops of the batter over the cream cheese filling. Using a knife, swirl through the batter and cream cheese filling, leaving a ½ inch border around the edges.

Bake 45-50 minutes in the preheated 325 degree oven until a toothpick inserted into the brownie center comes out clean. Let cool in the pan for one hour, then, using the parchment paper as “handles” carefully remove the brownies and set on a wire rack to cool completely.

TIP: To accurately test the doneness of the brownies, be sure to stick the toothpick into the brownie portion, not the cream cheese. Leftover brownies should be stored in the refrigerator. Let leftovers stand at room temperature for 1 hour before serving.