Lightly spray an 8-inch springform pan with cooking spray. Follow the instructions on your boxed brownie mix, combining ingredients as directed. Pour the brownie batter into the prepared pan and spread evenly. Bake at 350°F for the time indicated on the package, or until a toothpick comes out clean. Let cool completely.

In a microwave-safe bowl, combine the 60% cocoa chocolate chips. Microwave in 30-second intervals, stirring between each until melted and smooth, this takes about 1 to 2 minutes. Allow to cool slightly.

In a stand mixer, add softened cream cheese, sugar, and butter. Beat on medium speed until creamy, about 2-3 minutes. Gradually add the cooled melted chocolate, mixing until well combined.

Gently fold the thawed Cool Whip into the chocolate cream cheese mixture, being careful not to over-mix. Add the semi-sweet chocolate chips, stirring to distribute evenly.

Spread the cheesecake filling over the cooled brownie crust, smoothing with a spatula. Refrigerate for at least one hour to firm up.

Before serving, drizzle hot fudge sauce over the top of the cheesecake. Optionally, pipe chocolate whipped cream around the edges for decoration.