Texas Sheet Cake (from Aunt Dorothy)

INGREDIENTS

• :
• 1 cup vegetable shortening
• 1 cup water
• 4 tablespoons unsweetened cocoa powder
• 2 cups all-purpose flour
• 2 cups granulated sugar
• ½ teaspoon salt
• ½ cup sour cream
• 2 eggs
• 1 teaspoon baking soda
• ¼ cup vegetable shortening
• 6 tablespoons whole milk
• 4 cups powdered sugar
• 1 teaspoon vanilla extract
• 1 cup chopped walnuts or pecans