5 ounces bittersweet chocolate (70% cocoa), chopped
Two 8-ounce packages cream cheese, at room temperature
1/2 cup + 3 tablespoons granulated white sugar
2 tablespoons unsweetened cocoa powder
2 large eggs
1 3/4 cups all-purpose flour
1 1/2 cups granulated white sugar
2/3 cup unsweetened cocoa powder (not Dutch process)
1 1/2 teaspoons baking soda
1/2 teaspoon baking powder
1/2 teaspoon salt
1 teaspoon instant espresso powder
3 large eggs, at room temperature
1 1/4 cups buttermilk, divided
3/4 cup unsalted butter, at room temperature
1 teaspoon vanilla extract
CHOCOLATE SOUR CREAM FROSTING:
2 cups semisweet chocolate chips
1/2 cup (1 stick) unsalted butter, at room temperature
1 cup sour cream
2 tablespoons light (white or golden) corn syrup
1. Prepare the cheesecake layer: Preheat oven to 325 degrees F. Place a large roasting pan on the lower third rack of the oven. Place a kettle of water on the stove to boil. Spray a 9-inch springform pan with nonstick spray and line the bottom with a round of parchment paper. Wrap a double layer of foil around the bottom and up the sides of the pan (you want to seal it so the water from the water bath doesn’t seep into the pan). Place chocolate in a medium glass bowl. Melt in the microwave in 30 second bursts until the chocolate is melted and smooth, stirring after each burst. Set the chocolate aside and let it cool off until it is lukewarm but still pourable. In a large bowl, use an electric mixer to mix the cream cheese- blend until it is nice and smooth and creamy. Mix in sugar and cocoa powder and blend until incorporated, scraping down sides of the bowl as needed. Add eggs, one at a time, blending after each addition. Mix in the lukewarm chocolate. Mix until smooth. The batter will be very thick- scrape it into the prepared pan and smooth the top. Set the pan into the roasting pan in the pre-heated oven. Carefully pour the hot water from your kettle into the roasting pan (it will fill the pan surrounding the cheesecake). Pour enough water so that there is about an inch of water coming up the foil along the sides of the cheesecake pan. Bake the cheesecake for 45 minutes. It should be set to the touch and not jiggly. Remove the cheesecake from the roasting pan and let it cool on a wire rack for at least an hour. When it has cooled, place the pan into the freezer and let the cheesecake freeze completely. This can be done in several hours- or overnight.
2. Prepare the cake layers: Preheat oven to 350 degrees F. Grease and flour two 9-inch round metal baking pans (or spray with nonstick baking spray with flour). In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder and salt. Add espresso powder, eggs, 1/4 cup of the buttermilk, butter and vanilla to the flour mixture. Using an electric mixer on medium-low speed, beat for 1 minute, until blended. Scrape sides and bottom of bowl with a rubber spatula. Beat on high speed for 2 minutes. Add the remaining buttermilk and beat on low speed for 15 to 30 seconds, until just blended. Spread the batter evenly into the prepared pans, dividing equally. Bake 30 to 35 minutes or until a toothpick inserted in the center comes out with a few moist crumbs attached. Let cool in pans on a wire rack for 10 minutes. Run a knife around the edge of the pans, then invert cakes onto a rack to cool completely.
3. Prepare the frosting: In a large microwave-safe bowl, combine the chocolate chips and butter. Microwave 1 to 2 minutes, stopping every 30 seconds to stir, until melted and smooth. Whisk the sour cream and corn syrup into the chocolate mixture until smooth. Cover and refrigerate for at least 30 minutes or until firm enough to spread.
4. Assemble the cake: Place one cake layer into the center of a cake plate or platter. Remove the cheesecake from the freezer, take off the sides of the pan, and slide a knife under the parchment to remove the cheesecake from the pan. Peel off the parchment. Measure your cheesecake layer against the cake layers. If the cheesecake layer turns out to be a slightly larger round than your cake, move it to a cutting board and gently shave off some of the exterior of the cheesecake (with a sharp knife) to get it to the same size as your cake layers. Place the cheesecake layer on top of the first cake layer. Place the 2nd cake layer on top of the cheesecake.
5. Frost the cake: Apply a crumb coat layer to the cake- use a long, thin spatula to cover the cake completely with a thin and even layer of frosting. Be sure to wipe off your spatula each time you are about to dip it back into the bowl to get more frosting (this way you won’t be transferring any crumbs into the bowl of frosting). Don’t worry at this point about the crumbs being visible in the frosting on the cake. When your cake has a thin layer of frosting all over it, place it into the refrigerator for 30 minutes to “set” the frosting. Once the first layer of frosting is set, apply the 2nd layer. Start by adding a large scoop of frosting onto the top of the cake. Use a long, thin spatula to spread the frosting evenly across the top and then spread it down the sides of the cake too. Because you applied a crumb-coat layer, you shouldn’t have any crumbs floating around in the final frosting layer. Decorate, as desired. I recommend white chocolate shavings (see *Tips below). Keep this cake refrigerated.
*Using a good quality bittersweet chocolate will make a difference in this recipe. Splurge for Scharffen Berger or something similar.
*For making white chocolate shavings: Purchase a hunk of white chocolate and a hunk of dark chocolate. Microwave the chocolate to soften it up slightly (15 to 30 seconds, depending on the size). Use a potato peeler to run down the side of the chocolate to create shards/shaves/curls of chocolate. I like to shave it onto a paper plater and then just use the plate to slide the chocolate onto the top of the cake.
*If you are serving this cake at a party, it’s perfectly okay to leave the cake at room temperature for an hour or so while serving. Otherwise, keep it refrigerated.