Melt the butter in a medium saucepan over medium heat, stirring frequently until completely melted, about 2-3 minutes.

Add mini marshmallows to the melted butter and stir continuously for about 3-4 minutes until fully melted and smooth.

Quickly add Fruity Pebbles cereal into the melted marshmallow mixture, folding gently until coated.

Transfer the mixture onto a large piece of parchment paper and press it into a rectangle about ½ inch thick. Cool for 5-10 minutes.

Lay out fruit roll-ups flat and ensure you have enough for your sushi rolls.

Place a banana at one edge of the cooled cereal rectangle and roll tightly to form a sushi roll.

Slice each sushi roll into 1-inch pieces and place them on a serving platter.

Drizzle chocolate syrup on top, if desired, and serve.