Grease your baking dish with a cooking spray or butter. Line if with parchment paper if you like, and set aside. Preheat your oven to 350℉.
In one mixing bowl, mix together the flour, cocoa powder, and salt from the brownie mix.
1½ Cups Flour, 1 Cup Cocoa Powder, ½ Tsp Salt
In another bowl, mix together the butter and sugar, and cream them together until well combined and fluffy.
1 Cup Butter, 2⅓ Cups Sugar
Add the four eggs and tablespoon of vanilla to the butter-sugar mix and stir to combine. Then, fold in the flour mixture and stir. Mix but don't over-mix, to avoid gluten formation.
1 Tbsp Vanilla Extract, 4 Eggs
In your stand mixer, beat together the cream cheese, egg, vanilla, and sugar from the cheesecake list, until smooth and creamy.
8 Oz. Cream Cheese, 1 Egg, 1 Tsp Vanilla Extract, ⅓ Cup Sugar
Spread half of the brownie batter across the bottom of the baking dish in an even layer. It will be thick, so spread it smooth with a rubber spatula if you need to.
Drop spoonfuls of cheesecake mix over the brownie mix and spread it out, almost but not quite to the edge. Drizzle raspberry coulis over this.
½ Cup Raspberry Coulis
Swirl the cheesecake and raspberry together, trying not to mix it into the brownie mix below.
Drop spoonfuls of the remaining brownie mix over the top of all of this, and repeat the swirl process to smooth it out and spread it evenly.
Bake the brownies for 40 minutes, then remove and let cool for an hour or so before serving.