Preheat your oven to 350°F (175°C) and prepare an 8x8-inch baking pan with cooking spray and parchment paper.
Mix softened cream cheese and unsalted butter until creamy and smooth.
Melt semi-sweet or bittersweet chocolate with remaining unsalted butter in a microwave-safe bowl.
Add granulated sugar, then mix in the large eggs one at a time along with the vanilla extract.
Whisk together flour, cocoa powder, kosher salt, and baking powder in a separate bowl before folding into the chocolate mixture.
Pour half the chocolate batter into the prepared pan, dollop the cream cheese mixture on top, and spoon remaining chocolate batter over it. Swirl to create patterns.
Bake for 40-45 minutes until a toothpick comes out with a few crumbs. Let cool for at least 1 hour.
Lift cooled brownies out using parchment overhang and cut into 16 squares.
Notes
Ensure all ingredients are at room temperature for best results. Allowing the brownies to cool completely before slicing enhances texture.