SPONGE CAKE: Cut your parchment paper to fit three 8" circular pans perfectly, then use an edible marker to trace your desired design onto one parchment round.

Grease your pans with cooking spray and line them with the parchment rounds. [This makes three layers of sponge cake. You can also just use a standard-size cookie sheet, note that using a standard-size cookie sheet will only make two layers instead of three.]

Separate the egg whites from the egg yolks. We are using every part of the egg in this recipe so hang onto both. Place the egg whites in a large bowl and the egg yolks into an even larger bowl. Set the egg whites aside, we will need them later.

Whisk together the egg yolks, ½ c sugar, vegetable oil, milk, and vanilla until smooth.

Sift the flour and cornstarch into the egg yolk mixture. Whisk until the batter is nice and smooth. The batter will be thick. Set aside.

In the bowl of a stand mixer fit with a whisk attachment, whisk the egg whites from earlier until frothy. Slowly add remaining ½ c sugar and vinegar to the egg whites.

Whisk the egg whites until stiff peaks form. This is very important. Stiff peaks should be able to stand up straight when the whisk is lifted.

Add the egg whites to the egg yolk mixture. Gently fold in the egg whites. Be careful not to over-mix the batter. Over mixing will deflate the egg whites and make the batter, thin and runny. Mix until the egg whites are just evenly distributed and the batter has few streaks.

Preheat the oven to 375°.

Use small bowls to dye each color that you will need to make your design. Scoop a bit of the batter at a time into these small bowls to make every color you need. Place each color into a piping bag.

Pipe the design with your desired colors. Do your best to trace the design that you created earlier, with your piping bag.

Once you have the design finished, freeze or refrigerate it for 5-8 minutes so it sets and is nice and firm.

Pipe ⅓ of the original, uncolored batter on top of the frozen design. Pipe the remaining uncolored batter into the other two pans.

Bake for 8-10 minutes or until golden brown on the edges.

As soon as the cake comes out of the oven, flip the pan onto parchment paper. The design will be facing up. While the cake is still hot, peel off the parchment paper to reveal the beautiful design. Let the cakes cool before assembling.

WHIPPED CREAM: n the bowl of a stand mixer fitted with the whisk attachment, whisk the cream, sugar, and vanilla until stiff peaks have formed and you have reached a whipped cream consistency.

ASSEMBLY: Once the cakes have cooled, layer the cakes with evenly spread whipped cream between each layer. If desired, add fresh fruit marmalade, or Nutella. Use the designed sheet cake as the top layer.

Feel free to trim the sides to clean it up a bit if you wish to give the cake a more complete look.