For the Chocolate Pudding/Frosting:

• ½ cup unsweetened Dutch-processed cocoa powder
• 1 cup water
• 1 cup milk
• ¾ cup granulated sugar, divided
• 4 egg yolks
• 1/3 cup cornstarch
• 2 ounces semi-sweet chocolate, chopped
• 2 tablespoons unsalted butter, cubed
• 1 teaspoon pure vanilla extract
• pinch salt

For the Devil’s Food Cake:

• 3 ounces bittersweet chocolate, finely chopped
• ¾ cup boiling water
• 1 tablespoon instant espresso powder
• 2 cup all-purpose flour
• ½ cup unsweetened cocoa powder
• ¼ cup unsweetened black cocoa powder
• 1 teaspoon baking soda
• ¾ teaspoon baking powder
• ¾ teaspoon salt
• ¾ cup unsalted butter, softened
• 3 tablespoons canola oil
• ¾ cup packed brown sugar
• ¾ cup white sugar
• 4 large eggs
• 2 egg yolks
• ¾ cup milk

To Decorate (optional):

• 4 tablespoons unsalted butter, softened
• 1 cup confectioners’ sugar
• 1 to 2 teaspoons milk or heavy cream
• ¼ teaspoon vanilla extract
• gel food coloring
• silver dragees or sugar pearls

Instructions

Make the Chocolate Pudding/Frosting:

1. In a medium saucepan, thoroughly whisk together the cocoa powder, water, milk, and ¼ cup of the granulated sugar. Place the mixture over medium-high heat and bring it to a gentle simmer, stirring occasionally.
2. While the milk mixture is heating, combine the egg yolks with the remaining ½ cup of sugar in a separate mixing bowl and whisk until well blended. Just before the milk mixture reaches a full simmer, stir the cornstarch into the egg mixture until smooth.
3. Carefully temper the simmering milk mixture into the egg mixture. This is done by slowly whisking a small amount of the hot milk into the egg mixture at a time, gradually increasing the temperature of the eggs without cooking them. Once tempered, return the entire egg-milk mixture back to the saucepan.
4. Continue to cook the pudding mixture over medium-low heat, stirring constantly with a whisk, until it visibly thickens and large bubbles begin to pop on the surface, indicating it’s cooked through. Remove from heat and immediately stir in the chopped semi-sweet chocolate and cubed unsalted butter until the mixture is completely smooth and glossy.
5. For an ultra-smooth pudding, strain the mixture through a fine-mesh sieve into a clean bowl. Stir in the vanilla extract and a pinch of salt. To prevent a skin from forming, press a piece of plastic wrap directly onto the surface of the pudding. Chill in the refrigerator until the pudding is completely cool and firm, which will take approximately 4 hours or, ideally, overnight.

Make the Devil’s Food Cake:

1. Pre-heat your oven to 350°F (175°C). Prepare three 8-inch round cake pans by greasing them well and lining the bottoms with parchment paper. Set aside.
2. In a large coffee mug or a heat-safe bowl, combine the finely chopped bittersweet chocolate and instant espresso powder. Pour the boiling water over the top and whisk until the chocolate is completely melted and smooth. To keep this mixture warm, place one of your prepared cake pans on top of the mug/bowl and set aside.
3. In a separate medium bowl, sift together the all-purpose flour, both unsweetened cocoa powders (regular and black), baking soda, baking powder, and salt. Whisk to ensure they are thoroughly combined, then set aside.
4. In the bowl of a stand mixer fitted with a paddle attachment, cream the softened unsalted butter on medium speed until it is smooth and uniform. Add both the brown sugar and white sugar, then beat on medium speed for 2 to 3 minutes until the mixture is light, fluffy, and pale in color. Reduce the mixer speed to low and add the large eggs and egg yolks one at a time, mixing well after each addition. Stop the mixer and use a spatula to scrape down the bottom and sides of the bowl to ensure everything is incorporated.
5. With the mixer still on low speed, gradually add in about half of the sifted dry flour mixture, mixing just until it is combined. Stream in the milk and mix until it is fully absorbed into the batter. Add the remaining half of the flour mixture and mix until just combined. Finally, slowly stream in the melted chocolate and espresso mixture, mixing until the batter is smooth and homogeneous. Be careful not to overmix.
6. Evenly divide the cake batter among the three prepared 8-inch cake pans. Bake for 22 to 25 minutes, or until a wooden toothpick inserted into the center of the cakes comes out clean, indicating they are fully baked. Allow the cakes to cool on a wire rack in their pans for 15 to 20 minutes before carefully inverting them and removing them from the pans to cool completely.
7. Once the cake layers have completely cooled, use a long, serrated knife to carefully level the tops of the cakes, creating flat surfaces. Be generous with your cuts here; these scraps are crucial for the signature crumb coating, so resist the urge to snack on them!

Assemble the Cake:

1. Remove the chilled chocolate pudding from the refrigerator and gently whisk it to loosen its consistency, making it spreadable. Place one layer of cake on a cake board or your desired serving dish. Using an offset spatula, spread approximately 1/3 of the chocolate pudding evenly over the cake layer. Carefully place the next cake layer on top and repeat the pudding application. Finally, place the last cake layer on top, with its cut-side facing down for a flat surface. Chill the assembled cake in the refrigerator for about 10 minutes to help set the pudding layers.
2. Once chilled, take the cake out of the fridge and use the remaining chocolate pudding to apply a thin, even layer over the entire exterior of the cake (sides and top). This layer acts as a crumb coat and will provide an adhesive surface for the cake crumbs. Return the cake to the refrigerator for an additional 5 to 10 minutes to allow this outer pudding layer to slightly set.
3. Meanwhile, prepare your cake crumbs. Take the leveled cake tops and crumble them into fine pieces. You can achieve this using a food processor for very fine crumbs, a box grater for a slightly coarser texture, or simply your hands for a rustic look. Ensure the crumbs are fairly fine and uniform.
4. Remove the partially set cake from the refrigerator. Now, generously press the prepared cake crumbs onto the sides and top of the cake, covering it completely. This step can get a bit messy, so it’s advisable to work over a rimmed baking sheet. Any crumbs that fall onto the sheet can be reused and pressed back onto the cake, minimizing waste and ensuring full coverage.
5. To prevent the cake from drying out and to maintain its freshness, store the finished Brooklyn Blackout Cake in an airtight cake box or under a cake dome until you are ready to serve it.

Decorate the Cake (optional):

1. To make a small batch of decorative buttercream, combine the softened unsalted butter and confectioners’ sugar in a mixing bowl and beat until well blended. Add the milk (or heavy cream) and vanilla extract, then increase the mixer speed to medium-high and beat until the buttercream is light, fluffy, and creamy. If desired, add a few drops of gel food coloring of your choice and mix until the color is evenly distributed.
2. Transfer the prepared buttercream to a piping bag fitted with a star tip (or any desired decorative tip). Holding the piping bag straight down, pipe small, consistent stars or rosettes around the top edge of the cake for an elegant border. For an added touch of sparkle, gently place silver dragees or sugar pearls on top of each piped star.