Begin by spraying an 8×8 pan with nonstick cooking spray to ensure easy removal of your Jello Roll Ups later.

In a medium bowl, combine your chosen Jello powder with boiling water, whisking vigorously for about 2–3 minutes until fully dissolved.

Add the mini marshmallows to your dissolved Jello mixture and heat in the microwave for 1 minute and 30 seconds, whisk until smooth.

Carefully pour the Jello and marshmallow mixture into the prepared pan and refrigerate for about 2 hours until firm.

Once set, run a knife along the edges of the pan to loosen the Jello sheet, then roll it tightly from one end.

Slice the rolled Jello into ½ inch slices and arrange them on a platter to serve.