The Most Amazing Texas Sheet Cake is light and fluffy with a deliciously decadent cooked frosting on top. Sprinkle on some chopped pecans or walnuts and you have a sheet cake that people will rave over!
Preheat oven to 350 degrees. Lightly grease a 13x18 inch baking sheet.
In a large mixing bowl stir together flour, sugar, cocoa, baking soda, and salt.
Add eggs, buttermilk, warm water, oil, and vanilla. Whisk until combined and batter is smooth. This should take just a couple of minutes. Pour batter into prepared baking sheet.
Bake for 20-25 minutes until a toothpick inserted into the center comes out clean. Cool on a wire rack for 15 minutes before frosting.
FOR THE FROSTING
Melt butter in a medium-sized saucepan over low heat. Whisk in cocoa powder, then pour in buttermilk. Increase heat to medium high and bring to a simmer, whisking constantly.
Once the mixture is simmering, remove from the heat and whisk in powdered sugar and vanilla until smooth. Pour over cake to cover. Use a rubber spatula to smooth out and spread if needed. Sprinkle on chopped pecans. Let the cake and frosting cool completely before cutting and serving.