Preheat the oven to 350 degrees. Prepare 3 – 8" round pans by either greasing and lining the bottom with parchment or coating the bottom and sides with bakers release.
In a large mixing bowl, combine the sugar, oil, eggs, and mint chocolate chip flavor. Beat on medium for about 2 minutes. The mixture should be slightly lighter in color. Stir in the sour cream until incorporated.
Add half of the dry mixture to the egg mixture along with half of the milk. Mix on low until the flour is mostly mixed in. Scrape down the sides of the bowl and then add the remaining dry ingredients, milk, and food color. Beat on low until all of the ingredients are well incorporated.
Bake for 25-30 minutes, or until the toothpick test comes out clean. You can also test by gently pressing the center of the cake – if it springs back – the cake is done. Be sure to rotate the cakes in the oven about halfway through the baking process.
Once done, remove from the oven and allow to cool until the cakes reach room temperature. Remove the cakes from the pan and wrap each individually in plastic wrap and place them in the freezer. They should be frozen prior to assembling the cake.
Make the icing as one large batch. If you would like to make separate colors as I did, separate into bowls and color as you wish. Decorate the cake as you usually would, using my cake photo as inspiration.