Spread the peanut butter on half of the bread slices, keeping most of it in the center. Top it with jelly, keeping it in the middle of the sandwich, and top it with another bread slice to closethe sandwich. Make as many as needed.
Seal & remove the crusts:
Place the sandwich cutter in the middle of the sandwich. Push the sealer down and hold it to seal for 15 to 30 seconds. Remove the crusts from around the sealer and then lift the sealer.
Freeze for later:
If making a lot, place them on a parchment-lined baking sheet and freeze. Once frozen, transfer them into a large zip bag and keep them frozen. Or, place each uncrustable inside a sandwich size zip bag and freeze individually.
Pack for lunch:
Pack the frozen uncrustable inside the main compartment of a lunch box. Add any sides, like fruit and veggies, in separate compartments or containers. If the uncrustable is inside a zip bag, just add it directly inside the lunch bag.