Fancy Black Walnut Cake - Hammons Black Walnuts

Ingredients

• ½ cup butter, softened
• ½ cup shortening
• 2 cups sugar
• 5 eggs, separated
• 1 cup buttermilk
• 1 teaspoon baking soda
• 2 cups all-purpose flour
• 1 teaspoon vanilla
• 1 ½ cups Hammons Black Walnuts
• 1–3 ounces flaked coconut
• ½ teaspoon cream of tartar