Preheat the oven to 350 degrees F. Prep an 8x8 inch baking dish by spraying it with cooking spray or lining it with parchment paper.
Prepare brownie batter following instructions from the box mix.
Measure ½ cup of brownie batter and set it aside. Pour the rest of the brownie batter into the prepared baking dish.
Bake brownies in oven for 28-33 minutes or until just cooked. A tester should have a couple of crumbs attached to it, but you shouldn’t see raw batter.
While the brownies are cooking, make the cream cheese layer. Use a mixer to beat the cream cheese until smooth.
Slowly beat in the vanilla Greek yogurt, granulated, white sugar, egg, powdered sugar, vanilla extract, and salt until combined.
Pour cream cheese mixture over cooked brownies in baking dish. Be sure to create an even layer. You do not need to wait for the brownies to cool.
With remaining brownie batter, drop dollops of batter throughout the baking dish and then use a fork or knife to create swirls throughout.
Bake in the oven for 25-30 minutes or until the cream cheese layer is set and no longer loose and jiggly (a little wobble is okay).
Cool completely before cooking and servings.
PRO-TIP: For the best texture and to ensure success every time and not overcook the cheesecake layer, the brownies need to be baked first until they are cooked through before adding the cream cheese layer. If you would like to use a 9x13 inch pan, you do not have to prebake the brownie base, but you will have a thinner brownie.