Preheat oven to 350 f and separately prepare cake mixes according to package.
Checkered marble cake pan set recipe.
Place 2 of the cake pans on a middle rack in the oven and the third cake pan on the lower rack.
Stir cocoa into half of the batter.
In medium bowl beat cake mix milk cream cheese vanilla and eggs with electric mixer on low speed 30 seconds scraping bowl constantly then on medium speed 2 minutes.
The lower cake should be in between the two cakes above it.
Bake for 20 minutes.
Don t place it directly below one of the cakes or they ll bake unevenly.
Since i was using a standard 9x13 cake pan i increased the recipe by half.
Spread a thin layer of frosting on top.
Place a 8 chocolate cake ring on top of the first cake layer then place a 6 vanilla ring inside followed by a 4 chocolate ring then the 2 vanilla round.
Cool in pan 10 minutes.
Grease and flour pans then position dividers equally across pan tape to fit securely.
Follow filling instructions for 2nd and 3rd pan.
Divide batter in half.
For example i used 3 cups of flour 3 teaspoons baking powder etc.
Bake 30 35 minutes or until toothpick inserted in center comes out clean.
Dividers and tape will be removed before baking.
Each pan will use 3 dividers for four sections of batter check to be certain pieces fit snugly in pans.