Thaw out the dinner rolls so that they are soft, but still cold. Spray a clean surface with cooking spray and combine dough balls together. Roll dough into a rectangle about 11x16 inches.
With a pizza cutter, cut the rectangle in half, at about 8”. Then cut each half into 4 triangles so you will have 8 total. Place chocolate chips and marshmallows at the wide end of each triangle and begin to roll into a croissant. Make sure your croissant has no openings, smash the edges together to tighten the seams.
Spray a cookie sheet with cooking spray and place the 8 croissants on it. Cover with plastic wrap sprayed in cooking spray and let rise another 2 hours. Lightly beat one egg and brush the egg wash over the tops of the croissants. Preheat oven to 350 degrees and bake 12-14 minutes. Melt extra chocolate chips and drizzle over tops of croissants.