How to Make the Ultimate Blackout Cake

Difficulty: Moderately Challenging

Instructions

Step 1

This recipe makes one layer; so you'll have to make it three times. Cut three parchment paper liners for the pan. Butter the bottom of the pan, put a liner into the pan, then butter the liner and the sides of the pan. Lightly dust entire interior with cocoa.
Step 2

Heat oven to 350 degrees F. Heat buttermilk and butter in microwave in Pyrex cup, until butter is melted. Allow mixture to cool to lukewarm. Sift all dry ingredients into large mixing bowl.
Step 3

Add egg and vanilla to buttermilk mixture, combine thoroughly. Add liquids to dry ingredients. Stir gently with whisk until ingredients are well combined. A few small lumps may remain. Batter will be thin.
Step 4

Pour batter into prepared pan. Bake in center of oven for 30 to 35 minutes--or until the top springs back when gently pushed. Do not overbake.
Step 5

Cool in pan 15 minutes. Loosen edges of cake with sharp knife, then invert onto rack. Carefully peel paper from bottom of cake. Finish cooling upright on rack, then carefully slice in half horizontally. If tops of layers are domed, slice small amount of cake off top to make level. Save the trimmings.

Step 1

In a small bowl, whisk 1 cup of water and the cornstarch to dissolve cornstarch.
Step 2

Combine 4 cups of water, sugar, corn syrup and cocoa powder in a large saucepan. Bring to a boil over medium-high heat, whisking occasionally.
Step 3

Add the cornstarch mixture to 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.
Step 4

Remove from the heat and stir in the butter and vanilla, until thoroughly combined. Pour into a bowl.
Step 5

Cover with plastic wrap. Chill until firm.

Step 1

Combine chopped chocolates and butter in large, heatproof bowl. Set over simmering water on low heat (water should not touch bottom of bowl). Stir frequently until melted and smooth. Remove from heat and set aside. Discard hot water.
Step 2

In heavy-bottomed saucepan, combine eggs, sugar, and salt. Beat thoroughly to combine. Add coffee, and then water, beating to mix after each addition. Cook over medium heat, stirring constantly, until mixture registers 170 degree F on a candy thermometer. Immediately remove from heat.
Step 3

Immediately strain about one-quarter of hot egg mixture into melted chocolate mixture and whisk well to combine. Slowly strain remaining hot egg mixture into chocolate mixture, whisking thoroughly after each addition. Scrape sides and bottom of bowl periodically with rubber spatula to ensure thorough blending. Cool slightly, then chill.
Step 4

Whisk occasionally until frosting begins to thicken, then scrape bowl sides and bottom with rubber spatula and whisk frequently until frosting is of spreading consistency. When ready, frosting will have thickened considerably, and it will hold soft peaks (just like a meringue or whipped cream) when the whisk is lifted from it.

Step 1

Place strips of paper around edge of cake plate, to cover from edge into about 1 inch of where the cake will be. Place first layer of cake in center of plate, cut side up. If desired, brush 2 tbsp. of liqueur onto cake surface. Add one cup of filling, and spread to within 1/2 inch of edge of layer.
Step 2

Add second layer, cut side up. Apply liqueur if using. Apply one cup of filling and spread as before. Continue with cake, liqueur and filling until you have five cake layers. Bottom four layers should be placed cut side up, top layer of cake should be placed with top side up. If using liqueur, brush surface of top layer. Place cake in refrigerator to chill.
Step 3

Take sixth cake layer and cake trimmings and crumble thoroughly.
Step 4

Apply frosting to top and sides of chilled cake. Make as even and smooth as possible. A handful at a time, apply cake crumbs to entire frosted surface, top and sides. If crumbs fall off, retrieve and reapply until as much of cake as possible is covered with crumbs.
Step 5

Remove paper strips from edge of cake plate. Gently cover cake with plastic wrap. Chill thoroughly.