Preheat the oven to 375 degrees and lay a sheet of parchment paper on top of a baking sheet.
Open up a can of crescent rolls and unroll dough on a preparation surface. Use a knife to separate the pieces of dough along the pre-scored lines.
Lay 3 pepperoni slices at the base of each "triangle" of crescent roll dough. Add about a Tablespoon of mozzarella cheese on top. Then roll up the crescent roll.
Pinch the sides to seal the pizza roll and place on parchment paper. Repeat with the rest of the rolls.
Double-check that all the rolls are sealed closed as best as possible, and place baking sheet in oven. Bake for 15 minutes.
Pull rolls out of the oven and allow them to cool for 5 minutes before serving.