New Yorkers are famously argumentative, and there’s nothing they like better than an argument about something that doesn’t exist – that way, no tiresome facts can interfere with the fun of arguing. One of Brooklyn’s longest-running arguments (after ‘Who makes the best pizza, Patsy’s or Totonno’s?’ and ‘Can you make a real egg cream without Fox’s U-bet chocolate syrup?’) is about Ebinger’s Blackout Cake. Can mere mortals make Blackout Cake, especially without the signature blue box?

Ebinger’s was a chain of bakeries in Brooklyn renowned for the purity of its ingredients, the sparkling cleanliness of its stores, and the deep chocolatiness of this cake. Even though the last Ebinger’s finally closed in 1972, some devotees kept Blackout Cakes in their freezers for years afterwards. Even though we didn’t have access to one of these “fossils” from another era, this recipe has been extensively tested on Ebinger’s fans, especially our friends Karen and Jeff, who grew up in Brooklyn. They’re a tough crowd, but they tell us we’ve finally got it right. The custard filling is finally the perfect deep, velvety, very, very, dark brown.

You can tell this is a commercial baking recipe by the vegetable shortening, which is often combined with butter to keep costs down and quality high. It’s not the same as real butter, but it belongs in this recipe for the light crumb it creates. Blackout Cake is best made all in one shot, and served the same day it is made.

Ingredients
Makes 8 to 10 servings 

8 tablespoons (1 stick) butter, softened at room temperature
¼ cup vegetable shortening
2 cups sugar
3 eggs
2 teaspoons pure vanilla extract
¾ cup unsweetened cocoa powder
1 teaspoon baking powder
1 teaspoon baking soda
½ teaspoon salt
2 ¼ cups cake flour
1 cup whole, 2% fat, or 1% fat milk
For the custard:
3 cups water
2 1/2 cups sugar
1 tablespoon corn syrup
1 ½ cups unsweetened cocoa powder
Scant 2/3 cup cornstarch
6 tablespoons unsalted butter, cut into pieces
½ teaspoon pure vanilla extract

Instructions

Preheat the oven to 375 degrees.

Butter and flour two 9-inch cake pans. Cut 2 circles of parchment paper or wax paper to fit the bottoms of the pans, then press them in.

In a mixer fitted with a whisk attachment (or using a hand mixer), cream the butter and shortening together. Add the sugar and mix until light and fluffy. One by one, add the eggs, mixing after each addition. With the mixer running at low speed, add the vanilla, cocoa, baking powder, baking soda, and salt and mix. With the mixer running at low speed, add about 1/3 of the cake flour, then about 1/3 of the milk, and mix. Repeat with the remaining cake flour and milk and mix.

Pour into the prepared pans and bake until dry and springy to the touch and a tester inserted into the center comes out clean (a few crumbs are OK), 30 to 35 minutes. Let cool in the pan for 15 minutes, then turn out onto wire racks and let cool completely, to room temperature.

Using a long serrated knife, cut the cake layers horizontally in half. Reserving 3 halves for the cake, put the remaining half in a food processor, breaking it up with your hands. Pulse into fine crumbs.

Meanwhile, make the custard: Pour 2 ½ cups of the water, the sugar, corn syrup and cocoa powder into a large nonreactive saucepan and bring to a boil over medium-high heat, whisking occasionally.

Meanwhile, in a small bowl, whisk the remaining ½ cup of water and the cornstarch. Whisk into the cocoa mixture in the saucepan and return the mixture to a boil, whisking constantly.
Cook, whisking constantly, until very thick, 3 to 4 minutes. Remove from the heat and stir in the butter and vanilla. Pour into a bowl. Cover with plastic wrap, lightly pressing the plastic against the surface to prevent a skin from forming. Chill until firm, about 45 minutes.

To finish the cake, place a cake layer on a cake plate or serving platter (reserving the most even layer for the top) and spread with cooled custard. Top with another layer of cake, then custard, then one more layer of cake. Cover the top and sides of the cake with the remaining custard. Coat the cake with the cake crumbs. Chill until ready to serve, at least 2 hours. Serve the same day.