Marian's Brownies (Texas Sheet Cake)

I've never made these but I've had them many times. Emily uses this as her go to recipe for brownies (and frosting with graham crackers). She tried them years ago at my mother-in-law's house and wanted the recipe.

Marian's Brownies

2 cups flour

2 cups sugar

1/2 tsp. salt

1 cup margarine

1 cup water

3 Tbsp. cocoa

2 eggs

1 tsp. soda

1/2 cup milk

1 tsp. vanilla

Mix water, cocoa and margarine and bring to a boil; pour over flour and sugar and salt. Mix eggs, soda, vanilla and milk in bowl. Add to rest of mixture and mix together. Pour into 2--9x13 pans and bake at 350 degrees for 20 minutes.

Icing:

1/2 cup margarine

3 Tbsp. cocoa

6 Tbsp. milk

1 tsp. vanilla

1 lb. powdered sugar