Preheat oven to 325 degrees. Prepare an 8x8 pan with cooking spray.
Take 2 pieces of tinfoil. Place one sheet firmly on the bottom and into the corners of the pan and up over the 2 edges of the pan. Using your other piece of tinfoil do the exact same thing in the other direction, covering the other 2 edges. Covering the edges will help you remove the baked brownies from the pan. Coat foil with cooking spray.
In a medium sized pot melt butter on low. Once melted butter coats the bottom of the pot add chocolate band melt. Keep the temperature on low. Stir regularly and remove from heat once melted.
In the meantime, in a large bowl mix flour, salt, baking powder, sugar, eggs, and vanilla together.
Add melted chocolate mixture and whisk until totally incorporated. Spread batter in prepared pan, reserving about ⅔ of a cup.
Spread cream cheese filling as evenly as possible over batter.
Using a spatula scrape the bowl with the reserved batter and drop spoonfuls all over the cream cheese filling, 6 to 8 times.
Using a knife, swirl batter through cream cheese filling, making a marbled pattern.
Bake until a toothpick inserted in center comes out with only few moist crumbs attached, 35-45 minutes. Rotate pan halfway through baking.
Let cool in pan on wire rack for at least an hour.
Remove from pan and cut in squares when ready to serve. Keep refrigerated and enjoy!