Ingredients:

For the chocolate cake layers:

1 3/4 cups all-purpose flour
2 cups granulated sugar
3/4 cup unsweetened cocoa powder
2 teaspoons baking powder
1 1/2 teaspoons baking soda
1 teaspoon salt
1 cup buttermilk, room temperature
1/2 cup vegetable oil
2 large eggs, room temperature
2 teaspoons vanilla extract
1 cup hot water
For the orange cheesecake layer:

2 packages (8 ounces each) cream cheese, softened
1/2 cup granulated sugar
1 tablespoon orange zest
1 teaspoon vanilla extract
2 large eggs
For the chocolate ganache:

1 cup semisweet chocolate chips
1/2 cup heavy cream

Directions:

Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans and line the bottoms with parchment paper. Grease and line a 9-inch springform pan for the cheesecake layer.
For the chocolate cake layers, in a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Add the buttermilk, vegetable oil, eggs, and vanilla extract. Beat on medium speed until well combined. Stir in the hot water until the batter is smooth. Divide the batter evenly between the two prepared cake pans.
Bake the chocolate cake layers for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.
For the orange cheesecake layer, beat the cream cheese and sugar together in a large bowl until smooth. Add the orange zest and vanilla extract, mixing until combined. Beat in the eggs one at a time, mixing well after each addition. Pour the cheesecake batter into the prepared springform pan.
Bake the cheesecake layer for 40-45 minutes, or until the center is set. Allow the cheesecake to cool completely in the pan, then refrigerate for at least 2 hours.
For the chocolate ganache, place the chocolate chips in a heatproof bowl. Heat the heavy cream until just boiling, then pour over the chocolate chips. Let sit for 5 minutes, then stir until smooth. Let the ganache cool slightly before using.
To assemble the cake, place one chocolate cake layer on a serving plate. Top with the orange cheesecake layer, then place the second chocolate cake layer on top. Pour the ganache over the top of the cake, letting it drip down the sides.
Refrigerate the assembled cake for at least 1 hour before serving.