Ever since I made Diane's Double Chocolate Sheet Cake, I've been looking for other chocolate sheet cake recipes (sometimes known as Texas chocolate sheet cake). They're simple, easy to make and, with the right recipe, taste really good. I'm also a fan of cakes that call for spreading frosting over the warm cake as an added measure of decadence. Plus, the advantage of sheet cakes is they're easy to package and there's plenty for sharing. So if you have end-of-school-year gatherings, graduation parties and summer picnics coming up, these are good candidates as a dessert made for a crowd.
I changed two things in this recipe. First I added a teaspoon of cinnamon to the batter. Diane's Double Chocolate Sheet Cake had cinnamon in it and I decided I liked that combination in a cake. Second, I made the cake in a 9" x 13" pan instead of an 11" x 15" pan, both to make the cake a little bit thicker than the normal sheet cake thickness and because I don't have an 11 x 15" pan with sides high enough to bake even a thin cake. Bear in mind though that makes it look less like the usual sheet cake that's supposed to be flat and thin. If you bake it in a smaller pan, you also need to adjust the baking time accordingly.
I really liked this cake - it had the perfect chocolate taste and cakey texture. The sweetness of the icing was a perfect complement to the dark chocolate flavor of the cake and had the added bonus of running down the sides for slightly more icing along the edges. The icing sets so you can stack the pieces on top of each other if needed and it's not too thick of a layer, even baked in a smaller pan. Remember to use a good, high quality cocoa for the best results.
1/3 cup unsweetened cocoa powder
1 cup water
1 cup (2 sticks) unsalted butter
2 cups all-purpose flour
2 cups granulated sugar
1 teaspoon baking soda
½ teaspoon salt
2 large eggs, lightly beaten
½ cup sour cream or buttermilk
1 teaspoon vanilla extract
Icing
6 tablespoons unsalted butter
¼ cup milk
3 tablespoons unsweetened cocoa powder
3 cups confectioners’ sugar
¾ cup finely chopped nuts of your choice
1 teaspoon vanilla extract
1. Preheat the oven to 350˚F. Butter an 11-by-15-inch pan. (I used a 9 x 13.)
2. Put the cocoa in a medium saucepan and gradually stir in the water. Bring to a boil, add the butter and let melt. Remove from the heat and set aside.
3. Sift the flour, sugar, baking soda and salt together onto a piece of waxed paper. Gradually stir the dry ingredients into the cocoa mixture. Add the eggs, sour cream or buttermilk, and vanilla to the cocoa mixture and stir until smooth.
4. Pour the batter into the prepared pan. Bake for 30 minutes, or until the cake is firm to the touch in the center.
5. While the cake is baking, make the icing: In a medium saucepan, combine the butter, milk and cocoa. Bring to a boil and stir to melt the butter. Add the confectioners’ sugar and beat until smooth. Stir in the nuts and vanilla.