Line up containers on a baking sheet or other flat, moveable surface.
In a medium mixing bowl, add the green jello and 1 cup boiling water. Stir until the jello is dissolved.
Add 3.5 ounces of sweetened condensed milk (¼ of the can) to the bowl and stir until dissolved.
Add 1 cup cold water to the bowl and stir to combine.
Pour 1 ounce of the green jello into each container. Place in the fridge for 1 hour or until set.
Repeat steps 2-5 for the yellow jello, pink jello, and blue jello (in that order). If the jello mixture is too warm, let it cool for 5-10 minutes before layering it on top of the chilled layer, as it could melt it and mix colors.
Once the final layer is set, top with a dollop of whipped topping using a frosting bag and 1M frosting tip, if desired. Sprinkle with pastel nonpareils and top with a Cadbury mini egg. Enjoy!
Notes
Storage: You can keep these cups covered in the fridge for up to 4 days, but hold off on the garnishes. To keep everything looking fresh, wait to add the whipped topping, sprinkles, and candy until the moment you're ready to serve.
Tips:
Select straight-sided containers: To keep your layers looking perfectly even, avoid cups that taper at the base. Using straight-sided containers ensures every layer appears uniform from top to bottom.
Ensure a level surface: Double-check that your cups are sitting completely flat in the fridge while they set. Even a slight tilt can ruin those crisp, horizontal lines you're aiming for.