Velvet Underground Chocolate Cake

From Judy Rosenberg's All-Butter Fresh Cream Sugar-Packed Baking Book

Cake Ingredients:
4 oz. unsweetened chocolate
2 cups granulated sugar
1 1/2 cups sifted all-purpose flour
3/4 tsp. baking soda
1/2 tsp. salt
1 cup hot strong brewed coffee
1/2 cup sour cream at room temperature
1/2 cup vegetable oil
2 large eggs, lightly beaten with a fork, at room temperature
1 recipe fudge filling
1 recipe mocha buttercream icing

Cake Instructions:
1. Preheat the oven to 345 F. Lightly grease two 8" layer cake pans with vegetable oil or butter, after lining them with parchment circles.
2. Melt the chocolate in the top of a double boiler placed over simmering water then turn off the heat.
3. Sift the sugar, flour, baking soda and salt together in a large mixing bowl
4. In a separate bowl blend the hot coffee, sour cream and vegetable oil with a whisk.
5. With the mixer on low speed, add the coffee mixture in a stream to the dry ingredients and mix until blended, about 35 seconds. Stop the mixer to scrape the bowl several times with a rubber spatula.
6. Add the eggs one at a time and mix on medium-low speed after each addition until smooth, about 15 seconds. Scrape the bowl each time. Add the chocolate and mix until the batter is uniform in colour, about 10 seconds more.
7. Divide the batter evenly between the prepared pans and place them on the centre rack of the oven.
8. Bake until the cake springs back to the touch and a tester inserted in the centre comes out dry (do not wait for a crust to form), 35 to 38 minutes.
9. Cool the layers in the pans on a rack before frosting.
10. Frost in between each layer with the fudge filling and frost the top and sides with the mocha buttercream icing.

Fudge Filling - Ingredients:
2 oz. unsweetened chocolate
2 tbls. unsalted butter
5 tbls. plus 1 1/2 tsp. sugar
6 tbls. hot water
1/2 tsp. vanilla extract
Fudge Filling - Instructions:
1. Place all ingredients except for vanilla in the top of a double boiler placed over simmering water and cook uncovered, stirring occasionally, until the chocolate is melted and the sugar is dissolved, 30 minutes. The mixture will be smooth and velvety.
2. Pour the fudge into a small bowl, stir in the vanilla, and refrigerate until the mixture is thick and of spreading consistency, about 2 - 3 hours.

Mocha Buttercream Icing - Ingredients:
1/4 cup instant coffee powder
4 1/2 teaspoons water
8 tbls. unsalted butter, at room temperature
1 1/4 cups confectioner's sugar
3/4 cup plus 2 tbls. heavy cream, chilled
Mocha Buttercream Icing - Instructions:
1. Dissolve the coffee in the water and place all the ingredients in a food processor and process until light and fluffy, about 5 minutes. Stop the machine several times to scrape down the side of the bowl with a rubber spatula.
2. Transfer icing to a medium size mixing bowl and, using the paddle attachment of an electric mixer, continue to beat on medium-high speed, until the buttercream is light brown and fluffy, 15 to 20 minutes, stopping the mixer several times to scrape down the sides of the bowl. Use icing within one hour or it will need rewhipping.