Preheat oven to 350 degrees. Spray three 9-inch cake pans with nonstick spray or butter, then lightly coat with flour. Set aside.
Prepare cake mix according to package directions.
Measure batter, then divide it into 3 equal portions in 3 separate bowls.
Add varying amounts of green food coloring to each bowl to create light, medium, and dark colored green batter.
Transfer batter to cake pans and bake until a toothpick inserted in the center comes out clean, about 10 to 12 minutes.
Remove cake pans from oven. Let cool slightly, then remove cake layers from pans and transfer to a wire rack to cool completely.
Once the cake layers have cooled completely, use the 2.5-inch cutter to cut each cake layer into 7 circles.
Cover a dark colored circle generously with frosting, then add a medium colored circle, and add more frosting. Finish with a light colored layer, topping with more frosting.
Use the flat edge of a knife to remove excess frosting from the sides of the cake.
Serve cakes immediately or store in a cool place. Enjoy!
Notes
For the brightest colors, make sure to use a a vanilla cake mix or a white cake mix. If you'd like to use homemade cake, look for a recipe that makes a traditional two-layer cake.Check out the info before this recipe card for helpful tips, step by step photos, and more St. Patrick's Day recipe ideas!