White Texas Sheet Cake

I found this cake on pinterest. What a find it is. It was so easy to make and not near as long to bake as a regual 9x13 inch cake. I love the vanilla butter flavor. I adapted it from friedalovesbread. So good.
Cake

1 cup butter
1 cup water
2 cups sugar
2 1/4 cups flour
1/2 teaspoons salt
1 teaspoon baking soda
2 eggs
1 teaspoons vanilla
1/2 cup sour cream

Frosting
1 cup butter
1/3 cup evaporated milk
1 teaspoon vanilla
5 cups powdered sugar
dash of salt
1 cup chopped pecans

1. Put butter and water in a large bowl.
2. Heat in the microwave for 2 minutes.
3. Stir until the butter in melted.
4. Add sugar, flour, baking soda, and salt.
5. Stir with a wire whisk until smooth.
6. Add eggs and vanilla. Beat well.
7. Stir in sour cream until it is all blended.
8. Pour into a 11x17 inch baking sheet that has been greased and flour.
9. Bake at 375 for 20-25 ,minutes.
10. Remove from the oven and make frosting.
11. Cook butter and milk in microwave for 3-4 minutes. Add powdered sugar, vanilla, and dash of salt.
12. Beat until smooth.
13. Add nuts and gently  spread on  warm cake.