While this sheet cake is Texan in name, it actually derives from a German. Well, not a resident or native of the European country, but an American named Sam German who invented the type of baking chocolate used in the original Texas Sheet Cake recipe. Once the recipe was published in the Dallas Morning News in 1957, it swept the country with its rich, buttery taste and impressive size—this cake alone feeds 32! And with a baking time of 30 minutes, you can whip it up in a flash. Texas Sheet Cake is a chocolatey, creamy potluck favorite...just make sure you save a slice for yourself.
Ingredients• 2 cups all-purpose flour, plus more for dusting the baking dish • 2 cups white sugar • 1 teaspoon baking soda • 1/2 teaspoon salt • 1/2 cup sour cream • 2 eggs • 1 cup butter • 1 cup water • 5 tablespoons unsweetened cocoa powder For the icing: • 5 tablespoons unsweetened cocoa powder • 1/2 cup butter • 6 tablespoons milk • 4 cups confectioners' sugar • 1 teaspoon vanilla extract • 1 cup chopped walnuts, plus more for topping (optional)
Preheat the oven to 350 degrees F.
Prepare a 10x15-inch baking dish by greasing it with nonstick cooking spray and flouring.
Combine the sugar, flour, salt, and baking soda in a bowl.
Beat in the eggs and sour cream. Set aside.
In a saucepan, melt the butter on low, then add in the cocoa and the water. Bring the mixture to a boil, then remove it from the heat.
Let the cocoa mixture cool slightly, about 5 minutes.
Stir the cocoa mixture into the egg mixture until fully blended.
Pour the batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 20 minutes.
Meanwhile, in a large saucepan on the stove-top over medium heat, combine 5 tablespoons of cocoa, 1/2 cup of butter, and milk to begin making the icing.
Bring the mixture to a boil, then remove it from the heat.
Mix in the vanilla and confectioners' sugar.
Fold in the nuts, mixing until fully combined.
Let the cake cool before frosting.
Serve frosted and topped with additional walnuts.