Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x13 inch pan.
In a saucepan, melt the butter with the water. Bring to a boil.
In a large bowl, combine the flour, sugar, baking soda and salt. Add the boiled mixture and stir until blended. Beat in the eggs, buttermilk, and vanilla. Stir in the melted chocolate and pecans. Pour into the prepared pan.
Bake for 25 to 30 minutes in the preheated oven, or until a toothpick inserted into the center of the cake comes out clean. Cool completely before frosting.
Interesting Facts
Texas Sheet Cake is a classic American dessert that originated in the Lone Star State.
The cake gets its name from the size of the baking pan it is traditionally made in – a large, thin sheet pan.
The cake is traditionally topped with a chocolate frosting.