Texas Sheet Cake is my absolute favorite cake. The cake itself is not too sweet but the fudge-like frosting is so incredibly rich and decadent. You won't be able to stop at 1 piece!
Preheat oven to 350. Mix together flour and sugar in a large bowl. Combine the butter, cocoa and water in a sauce pan and bring to a boil while stirring. Once boiling, turn off the heat and combine with the dry ingredients. Add 2 eggs, vanilla, baking soda and butter milk. Stir and mix well.
Pour batter into a well greased jelly roll pan (11"x17") and bake at 350 for 15-20 minutes. The cake is finished when a toothpick inserted into the middle comes out clean.
In a saucepan, combine butter, vanilla and cocoa. Bring to a boil. Add the milk slowly and combine. Add the powdered sugar 1/2 c at a time.
Pour and spread the frosting over the cake while still warm. Allow to cool completely. Cover with foil and store the cake at room temperature.