Spray cake pans with nonstick spray, then lightly coat with flour. Set aside.
Prepare cake mix according to package directions.
Measure cake batter, then divide evenly between three bowls.
Add food coloring to batter, mixing well to distribute evenly.
Transfer batter to prepared pans, then spread into an even layer with a spatula.
Bake cake until a toothpick inserted in center comes out mostly clean, about 8 to 12 minutes (watch closely).
Transfer pans to a wire baking rack, then let cake cool.
Decorate Cakes:
Use a 2.5-inch round cutter to cut 7 circles from each cake layer.
Cover a cake circle generously with frosting. Add another layer and frost, then add the final layer and frost the top. Repeat with remaining cake circles to make 7 individual cakes, each with 3 layers.
Use the flat side of a knife to remove excess frosting from the sides of the cakes.
Top cakes with mini eggs, pressing lightly into frosting.
Eat cakes immediately or store in an airtight container until ready to serve. Enjoy!
Notes
Check out info before this recipe card for tons of tips, variations, and step-by-step photos.