Chocolate Blackout Cake
Source: The Brooklyn Cookbook

CAKE
3/4 cup cocoa powder
1 cup milk
4 oz butter
1/4 cup shortening
2 cups sugar
3 eggs
2 tsp vanilla
2 1/4 cups cake flour
1 tsp baking powder
1 tsp baking soda
1/2 tsp salt

FILLING
2/3 cup sugar
2 tbsp cornstarch
1/4 tsp salt
1 1/2 cups milk
3 oz unsweetened chocolate, chopped
1 tsp vanilla

FROSTING
4 oz unsweetened chocolate
4 oz butter
1 1/2 tsp vanilla
3 eggs
3 cups confectioner's sugar

Preheat oven to 325 degrees F.

Cake:

Butter 2 (9-inch) cake pans, dust with flour, set aside. Stir cocoa with some milk to form a paste. Stir in the rest of the milk and beat with a whisk until smooth. Set aside. Cream the butter and shortening with the sugar. Add the eggs one at a time, mixing well after each addition. Add the vanilla and blend. Sift the flour with the baking powder, baking soda and salt. Add the flour mixture to the butter in three parts, alternating between each addition with the cocoa mixture, beating after each addition. BEAT ONLY TILL INGREDIENTS ARE ABSORBED. Divide batter equally in the two cake pans. Bake 35 to 40 minutes, or until cake pulls away from sides on pan, and a cake tester (toothpick) inserted into cake comes out clean. Place cakes on wire racks and allow to cool completely.

Filling:

Combine sugar, cornstarch and salt in small saucepan. Gradually add the milk while mixing with a wire whisk. Add the chopped chocolate. Place over medium heat and cook, stirring constantly, until mixture thickens and bubbles for three minutes. Filling should have the texture of pudding (because that's just what it is). Place in small bowl to cool with plastic wrap directly covering the surface to prevent a skin from forming.

Frosting:

Melt the chocolate in a double boiler. Remove from heat and allow to cool slightly. Beat butter, eggs and vanilla in bowl until mixed. Gradually add the sugar, 2 T at a time, beating well after each addition. Beat in the melted chocolate. Chill the frosting about 15 minutes.

Assembly:

Cut each cake in half horizontally. Three layers are for the cake, one for the cake crumb coating. Place one layer in a food processor and pulse to make crumbs.

Place half the filing on top of one cake layer, place second cake layer on top, place balance of filling on cake layer, top with remaining cake layer. Frost top and sides of cake with frosting. Working over a large baking sheet sprinkle cake crumbs liberally over top of cake and press onto side of cake.