Preheat the oven to 350F, and line a 9x9 pan with parchment paper.

In a medium bowl, whisk together the cream cheese, greek yogurt, and sugar until smooth and creamy.

Beat in the flour, followed by the eggs, vanilla, and salt. Stir until smooth, then set aside.

Now, make the brownie. In a medium, microwave-safe bowl, combine the chocolate chips, butter, milk, and sugar. Microwave for 30-45 seconds, until everything is smooth and melted.

Let cool slightly, then whisk in the eggs, one at a time, and the vanilla extract.

Stir in the flour, salt, baking powder, and baking soda.

Pour the brownie batter into the prepared pan, and pour the cheesecake topping on top.

Using a butter knife, gently swirl the brownie and cheesecake together to create a marbled effect.

Top brownie with more chocolate chips if desired.

Bake for 30-35 minutes, until the brownie does not jiggle and a toothpick inserted in the center comes out with just a few moist crumbs. Let cool to room temperature before removing from pan.