Arrange jelly, mason jars or dessert cups on a tray.
Crumble the pie crust and set aside.
Mix sweetened condensed milk and whipped topping together until combined.
Add in key lime juice and mix until fully blended.
Equally distribute the crumbled pie crust into the bottom of jars, about 1/2 inch high. (I reserve a little to sprinkle on top for garnish).
Carefully spoon filling into jars. (You can also place in a piping bag and pipe in, if desired) Fill to about 1/4 inch from the top of the jar
Chill in the refrigerator for 3 hours.
Pipe or spoon on additional whipped topping, graham cracker crumbs, mint, lime zest or sliced limes for garnish.