Prepare the 7" springform pan with a flour-based baking spray. Additionally, you can choose to add a parchment circle cut to fit the bottom of the pan, as well as, a parchment strip that is cut to the height of the pan. If you add the parchment paper, make sure to spray the pan once again.
For the brownie base, using a hand mixer or a stand mixer fitted with the paddle attachment, mix together the all-purpose flour, salt, baking powder, and unsweetened cocoa powder. Add in the unsalted butter, granulated sugar, large egg, and vanilla extract and mix until full combined. The brownie batter will have a thick consistency.
Place the brownie batter in the bottom of the prepared springform pan, and press down using a small spatula or your clean fingers to level. It won't be perfect—you just want the brownie batter to reach the sides of the pan.
Place the brownie base into the oven and bake for 350ºF for 30-35 minutes or until an inserted toothpick comes out with just a few brownie crumbs on it. If there is still batter on the toothpick, pop the springform pan back into the oven and monitor it every 1-2 minutes until it's done. Please careful though not to overtake the brownies.
Remove brownie base from the oven and allow to cool completely before adding the chocolate cheesecake layer.
For the chocolate cheesecake, place the semi-sweet chocolate chips into a small microwaveable bowl, and heat in the microwave in 30 second intervals at 50% power stirring in between until the chocolate is smooth and completely melted. This part took me 4 times. Set aside and allow too cool.
Using a hand-held mixer or a stand mixer fitted with the paddle attachment, beat together the cream cheese, granulated sugar, and unsalted butter on medium speed until smooth and creamy.
Carefully add in the melted chocolate and mix until completely blended, then stop the mixer to fold in the whipped topping with a spatula.
Spoon the chocolate cheesecake mixture on top of the cool brownie base. Smooth out the top with a small angled spatula.
Place the chocolate brownie cheesecake in the refrigerator to set for a minimum of 2 hours. If leaving overnight, you can cover it loosely with some plastic wrap.
When ready to serve, unlatch the sides of the springform pan and lift up.