This is delicious, and will stay fresh and moist for up to 6 days. The key to this cake is the double hit of chocolate, a cocoa-powder fudge, and additional melted chocolate. This cake will bake at 300 degrees for a long time- it is dense and requires a slower oven. Make sure the fudge mixture is at room temperature before you add it to the rest of the recipe.
¼ cup vanilla
¾ cup unsweetened cocoa powder
1-pound sweet butter, at room temperature
2 1/3 cups sugar
12 large eggs
11 ½ ounces unsweetened chocolate, melted
2 ½ cups cake flour
1-tablespoon baking soda
One 4 ½ -quart mixing bowl
One small bowl
Two 8 x 3 inch baking pans or one 12 x 3-inch round or square pan
Preheat the oven to 300 degrees. Butter the baking pans and line them with parchment. In a small saucepan, bring the water to a boil. Pour the boiling water into a bowl and add the cocoa powder and the vanilla, whisking vigorously until the mixture is smooth and no lumps remain. Set aside and let mixture cool to room temperature. In a standing mixer, cream the butter on medium speed for 3 minutes. Add sugar and mix for another 3 minutes, or until the batter is light in color and fluffy. Add the eggs, one at a time. Stop the mixer and scrape down the sides with a rubber spatula. Add the melted chocolate and mix on medium speed for 1 minute, until all the chocolate is incorporated. Sift the flour and baking soda together. Reduce the mixer speed to low, and alternate adding the flour and the cocoa mixtures. Pour into the prepared pans. Bake an 8-inch cake for 60 to 70 minutes at 300 degrees; a 12-inch cake may take two hours. This cake is dense and bakes more evenly in a slower oven. Test for doneness with a skewer inserted in the center of the cake- it should come out clean.