Spray 8 cups of a muffin tin with cooking spray and set aside.
On a large cutting board, separate the crescent rolls into triangles.
Combine cinnamon and sugar in a small bowl.
Dip each marshmallow into melted butter, then into the cinnamon and sugar mixture and place on a triangle crescent roll.
Starting with the wide end of the triangle roll the dough up around the marshmallow and seal the ends as best as you can so it doesn't leak. Repeat with remaining marshmallows and crescent rolls.
Dip the top part of the roll into the melter butter again and then into the cinnamon and sugar mixture.
Place sugar side up in a greased muffin tin.
Bake at 375 degrees for 10-15 minutes until golden. Allow to cool slightly before serving.