1
In a large mixing bowl, mix cake mix, eggs, water, and oil until well combined and transfer to a greased square baking pan.
2
Bake at 350° for 35-40 minutes, covering with foil halfway through.
3
Allow to cool completely, then press greased ramekin into the center and twist to remove.
4
Allow mini cake to slide out of ramekin and slice through the center to create 2 layers.
5
Place bottom layer back in ramekin, top with a layer of frosting, then place top layer of cake with another layer of frosting spread evenly to the edges.
6
Cover in rainbow nonpareils, allow to chill and slightly harden in the fridge, then take a center bite and enjoy!