Make the red jello according to the package directions (usually you’ll mix the powder with 1 cup of boiling water and 1 cup of cold water). 

Divide the jello between your cups and transfer them to the fridge until the jello has fully set (about 2 hours). 

Once the first jello layer has set, divide the cool whip between the cups. Make sure to smooth the top of the cool whip layer (I used an offset spatula but a spoon would also work).

Transfer the cups to the fridge to chill again-- about 2 hours. 

Make the blue jello according to the package directions (again, mix the powder with 1 cup of boiling water and 1 cup of cold water).

Divide the mixture between the cups and place them back in the fridge to set completely (about 2 hours). 

Top with red, white, and blue sprinkles (if desired) and enjoy chilled.

Store any leftovers in the fridge for up to two days.