Chocolate Doberge Cake

Preparation

1. To make the cake

   Step 1

   Preheat the oven to 350°F. Lightly coat three 9-inch cake pans with cooking spray, then line the bottoms of the pans with parchment paper and lightly spray the paper.

   Step 2

   In a medium bowl, sift together the flour, cocoa, and baking soda. In a large heatproof bowl, whisk together the eggs and sugar. Place the bowl over a pot of simmering water and whisk continuously until the mixture is warm enough to dissolve the sugar completely. Remove from the heat and transfer the eggs to the bowl of a stand mixer fitted with the whisk attachment or transfer to a very large bowl and use a handheld mixer. Whip on high speed until the mixture is thick and pale, 5 to 7 minutes. Add the vanilla paste and whip for 1 minute.

   Step 3

   Remove the bowl from the mixer and, using a rubber spatula, gently fold in the sifted dry ingredients in three portions, being careful not to deflate the egg mixture in the process. When incorporated, stream in the butter, also folding it into the batter.

   Step 4

   Divide the batter among the prepared cake pans and tap the pans gently on the counter to release any large air bubbles. Bake for about 20 minutes, rotating the pans after 8 minutes, until a cake tester comes out clean when inserted into the center of each cake. Let cool in the pans on a wire rack for 10 minutes. Place a wire rack over each pan, invert the cakes onto the racks, and remove the pans. Peel off the parchment. Let the cakes cool completely. The cakes can be wrapped in plastic wrap and kept at room temperature overnight or frozen for up to 1 month.

2. To make the pudding

   Step 5

   In a heavy-bottomed saucepot set over medium-high heat, combine the cream, milk, and vanilla paste. In a medium bowl, whisk together the sugar, cocoa, cornstarch, and salt. Add the eggs and whisk until smooth. Once the dairy mixture comes up to a scald (you will see bubbles around the perimeter of the liquid and a wisp of steam rising from the surface), remove the pot from the heat. Start streaming a small amount of the hot dairy into the egg mixture, whisking constantly to prevent the eggs from cooking. Continue whisking in the milk mixture, until most of the liquid has been incorporated into the egg mixture. Pour the mixture in the bowl into the saucepot and place the pot over medium heat. Cook, again whisking constantly, until the mixture thickens and bubbles. When bubbling, remove the pot from the heat and immediately whisk in the butter and chocolate until melted and combined. Pour the pudding into a 9-by-13-inch baking pan and place a sheet of plastic wrap directly on the surface of the pudding, then poke a few holes in the plastic to allow the steam to escape. Let cool completely before building the cake. The pudding can be covered and refrigerated for up to 2 days.

3. To make the buttercream

   Step 6

   In a heavy-bottomed saucepot, combine ½ cup plus 2 tablespoons of the sugar with the milk, vanilla paste, and salt. Place over high heat until it comes to a scald (you will see bubbles around the perimeter of the liquid and a wisp of steam from the surface); do not bring to a full boil.

   Step 7

   Meanwhile, in a medium bowl, whisk together the cornstarch and the remaining ½ cup plus 2 tablespoons sugar. Whisk in the eggs and egg yolks until smooth. Start streaming a small amount of the hot dairy into the egg mixture, whisking constantly to prevent the eggs from cooking. Continue whisking in the milk mixture until three-quarters of it has been incorporated. Pour the mixture in the bowl into the saucepot and place the pot over medium-high heat. Cook, again whisking constantly, until the mixture thickens and begins to bubble. Let it bubble for 1½ minutes, then remove from the heat and transfer to the bowl of a stand mixer fitted with the paddle attachment or transfer to a large bowl and use a handheld mixer. Mix on medium speed until completely cool, then beat in the butter, a few pieces at a time, until it is incorporated and the buttercream is creamy and smooth. The buttercream can be covered and refrigerated for up to 2 days; bring it to room temperature and beat it with the mixer to refresh it before using. 

4. To make the syrup

   Step 8

   In a heavy-bottomed saucepot set over medium-high heat, bring the sugar and water to a boil. Once the sugar has fully dissolved, let the syrup boil for 45 seconds, then remove from the heat and cool.

5. To assemble

   Step 9

   Using a large serrated knife, trim the domed tops of the cakes so they’re flat; save the scraps for snacking. Cut each cake horizontally into three even layers, creating nine layers total. Place the first layer on a platter and brush with about ⅓ cup of the simple syrup. Spread ⅔ cup of the pudding evenly over the cake, leaving about a ½-inch border around the perimeter. Top with another cake layer, brush with another ⅓ cup syrup, then spread evenly with ⅔ cup of the pudding, again leaving a ½-inch border. Repeat until you have stacked the last layer of cake. Brush the top layer with syrup. Refrigerate the cake for at least 45 minutes before frosting.

   Step 10

   Apply a layer of buttercream to the sides of the cake with a large offset spatula. Smooth out the sides as evenly as possible and then spread a smooth, even layer of buttercream across the top. Chill the cake for another hour to set, while you make the icing.

   Step 11

   Meanwhile, make the icing. Put the chocolate and salt in a heatproof bowl. Place a saucepot full of water over high heat and bring to a boil. Remove from the heat and set the bowl of chocolate over the hot water to melt; stir it often to melt the chocolate evenly. In a second pot, heat the cream to a scald (you will see bubbles around the perimeter of the liquid and a wisp of steam rising from the surface), then remove from the heat. Pour one third of the cream into the melted chocolate and whisk to combine. Carefully add the remaining cream in two portions, whisking after each addition, until the ganache is smooth, shiny, and incorporated. Set aside until the ganache cools and is just thick enough to stick to the cake when poured over the top, 15 to 20 minutes.

   Step 12

   Remove the cake from the refrigerator and pour the ganache evenly over the top. The cake can be served right away or stored in the refrigerator for up to 3 days.