Generously grease and flour three 9-inch cake pans. Line them with parchment circles.
Using a stand mixer, mix together the white cake mix, 3/4 cup vanilla yogurt, 1/2 cup water, 4 egg whites, and 1/4 cup oil for about 30 seconds until moistened and then beat for two minutes. Move cake batter to a different bowl and set aside. (You don't have to wash the mixing bowl and beater before moving on to the red velvet cake mix.)
Mix together the red velvet cake mix, 3/4 cup vanilla yogurt, 1/2 cup water, 4 egg whites, and 1/4 cup oil for about 30 seconds, until moistened and then beat for two minutes.
Divide the batter between three bowls. In the first bowl mix together 2 1/2 cups of white cake batter and 1/2 cup of red velvet cake batter. In the second bowl mix together 2 cups of white cake batter and 1 cup of red velvet cake batter. In the third bowl, put 3 cups of red velvet cake batter.
Spread the batter into the prepared pans.
Bake at 325 degrees for 35-45 minutes, until a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 30 minutes on a wire rack.
Carefully remove the cakes from the pans, peel off the parchment circles and cool completely on wire racks.
Once the cakes the cooled, level the cakes by using a serrated knife to cut off the rounded tops. Gently run the serrated knife over the rounded cake tops that you just cut off to make cake crumbs that will be used for decorating the cake. Set the cake crumbs aside.
Place the darkest red cake layer on a cake stand on a turntable. Spread about one cup of Fluffy Vanilla Cream Cheese Frosting (recipe below) on the first layer. Repeat with the two remaining layers going from darkest to lightest.
Use the remaining frosting to cover sides of the cake. Start with a thin layer of frosting and then top it with another layer. Level the sides with a large offset spatula or icing smoother.
Use the tip of an offset spatula to make stripes around the sides of the cake and a spiral on top of the cake.
Sprinkle some all three colors of cake crumbs on the top of the cake. Use a fork to move them around and spread them out.
Store in the fridge until ready to serve.
Fluffy Vanilla Cream Cheese Frosting
Use a stand mixer to beat a package of softened cream cheese for two minutes.
Mix in the powdered sugar until smooth.
Beat in the marshmallow cream and vanilla until smooth.