Preheat your oven to 325°F (160°C). Grease a 9x9-inch baking pan and line it with parchment paper. Blend 2 cups of Oreo cookies into fine crumbs and mix in 4 tablespoons of melted unsalted butter. Press the mixture into the prepared pan and bake for 12 minutes until slightly set.

Melt 8 ounces of chocolate in the microwave. Beat 24 oz of cream cheese, 1 cup of sugar, and 1/2 cup of cocoa powder until smooth. Add the melted chocolate, 1/2 cup heavy cream, and 1 tsp of vanilla. Incorporate 4 eggs one at a time, mixing on low.

Pour the cheesecake filling over the cooled crust and bake for 40-50 minutes until edges are set and the center jiggles slightly. Let cool in the oven with the door ajar for about 20 minutes.

Allow to cool completely on a wire rack for about 1 hour. Cover and chill in the refrigerator for at least 6 hours or overnight.

Heat 1/2 cup of heavy cream until steaming. Pour over 1 cup of chocolate chips. Let sit for a few minutes and stir until smooth.

Pour the ganache over the cheesecake and refrigerate for another 10 minutes. Remove from the pan and slice into bars. Serve with whipped cream or fresh berries.