Good-Cooking - Texas Sheet Cake

Ingredients

• 2 cups sifted all-purpose flour
• 1/2 cup sour cream
• 1/2 teaspoon salt
• 2 cups granulated sugar
• 1 teaspoon baking soda
• 2 eggs
• 1 cup (2 sticks) margarine
• 4 tablespoons cocoa
• 1 cup water
• 1 box confectioners' sugar
• 1 cup chopped pecans
• 1 teaspoon vanilla extract
• 1/2 cup (1 stick) margarine
• 6 tablespoons milk