Preheat oven according to directions on brownie mix.
Prepare brownies according to recipe or package directions. Place brownie batter into a greased muffin tin to form a cup. Bake for 10 minutes.
Remove tray from oven when cups are rising. Take a small spoon and deflate the centers of the cups while leaving the sides of the brownie cup untouched. Put back in the oven and bake for another 5 minutes.
Again, remove from oven and with a small spoon, deflate the centers of the cups while leaving the sides of the cookie cup untouched.
Place back in the oven again and continue to check them every five minutes and deflate the middle with a spoon to give them a cup shape. Mine took a bit over 20 minutes before they were baked completely.
Remove from oven and let cool completely.
In a mixing bowl, beat cream cheese, powdered sugar, sweetened condensed milk and cocoa powder on medium speed until smooth, about 1 to 2 minutes.
Add about 1 tbsp of cheesecake filling to each brownie cup. Top with mini chocolate chips, if desired.