28 Oreo cookies, divided, for the bottoms of the cake pans
2 packages (8 ounces each) cream cheese, room temperature
½ cup (100g) granulated sugar
2 large eggs, room temperature
1 teaspoon vanilla
13 Oreo cookies
1 cup semi-sweet chocolate chips
⅓ cup heavy cream
whipped topping, store-bought or homemade
Oreo cookies, for garnish
Preheat the oven to 350°F. Spray two 8-inch round cake pans with nonstick cooking spray and line each with parchment paper.
In the bowl of a stand mixer with a paddle attachment, mix together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
In a separate bowl, combine the buttermilk, oil, eggs, and vanilla.
With the stand mixer on low speed, slowly add the wet ingredients to the dry. With mixer still on low, add the coffee and mix just to combine. Scrape the bottom of the bowl with a rubber spatula.
Arrange 14 Oreo cookies on the bottom of each cake pan.
Evenly divide the batter between the prepared pans and bake for 35-40 minutes, or until a cake tester comes out clean. Some Oreos will rise up into the batter and that is okay!
When done, remove the cakes from the oven. Let them cool in the pans for 30 minutes; then turn them out onto a cooling rack to cool completely.
Store the cooled cakes in the refrigerator until ready for assembly.
Preheat the oven to 325°F. Spray an 8-inch spring-form pan with nonstick cooking spray and line it with parchment paper.
In the bowl of a stand mixer with a paddle attachment, add cream cheese and vanilla. Mix on medium-low speed for 30 seconds. Add in sugar and eggs and beat until smooth (3-5 minutes). Scrape down the sides of the bowl if needed.
Arrange the Oreos on the bottom of the pan.
Pour the cheesecake filling over the Oreos and and bake 40-45 minutes, or until set.
Set the pan on a wire rack and let the cheesecake cool completely.
Refrigerate for at least 6 hours before assembling cake.
In a small saucepan, bring heavy cream to a boil. Remove from heat.
With chocolate chips in a heat safe bowl, pour cream over chips and slowly stir until all chips are melted.
Let sit to cool and thicken.
Make sure cheesecake and cakes are very chilled.
Place one layer of the chocolate cake on a cake stand. Try to get the side with the Oreos on the bottom, or facing down.
Gently place the cheesecake on top of chocolate cake, again, with the Oreo cookies on the bottom.
Place the second layer of chocolate cake (Oreos on the bottom) on top of the cheesecake.
Cover with cooled chocolate ganache.
Put whipped topping in a piping bag fitted with a closed star tip and pipe out dollops on top of the cake.
Press Oreos that have been halved into whipped cream dollops.