Red and green gel food coloring (the gel won’t thin out the icing)
2 cans vanilla/white frosting
¼ cup chocolate chips for decoration
Directions
Start by preheating the oven to 350 degrees.
[Do not follow directions on the cake mix box] In a large bowl with a hand mixer or stand mixer, add the cake mix and gelatin.
Add the oil, eggs, and water. Mix on low for 30 seconds, turn to medium and beat another 1-2 minutes or until fully incorporated.
Split the mixture between 2 greased and floured 9” round pans. (Fully greasing & flouring keeps the gelatin in the mixture from sticking to the pan.)
Bake for about 30-35 minutes, then remove from the oven and set aside to cool.
While baking & cooling, fill a small piping bag or sandwich bag with ¼ cup of vanilla frosting. This will be for the top of the cake.
Next, empty the rest of the first can of frosting into a bowl and mix in green food coloring. Do the same with the other can and red. Add colors slowly and gradually until you reach your desired color level.
Once the cake layers are completely cool, turn out of the pans. Place the first layer on a large platter, add a scoop of red frosting, and spread all over the top to within ¼" of the edge.
Add the second layer and dollop green around the edges, using a small silicone spatula or angled spatula to smooth icing down around the sides of the cake.
Once the edges are finished, spread green 1” around the top of the cake.
Add a nice scoop of red to the very center of the top of the cake. Using a silicone spatula or large angled spatula spread around the top out to meet the green edge.
Pipe the white icing to cover the red/ green seam to create the rind.
Dot the top of the cake with chocolate chips to resemble the watermelon seeds.
Slice and serve when ready. Store any leftovers covered in the fridge for up to a week.