To assemble the cookies: Scoop 1-2 tsp of sugar cookie dough into your hand and flatten it into a pancake about 1 inch wide. Repeat this step with another piece of dough. Place a ball of frozen Nutella on the top of the first sugar cookie patty, then place the second sugar cookie patty on top of the Nutella. Gently pinch the two dough pieces around the sides so that the cookie is sealed. Loosely roll the cookie between the palm your hands, forming an oblong ball, then roll cookie in sugar. Place finished cookie on the prepared baking sheet. Repeat these steps with the rest of the dough and Nutella, spacing cookies 2 inches apart. Use the wet and dry paper towels to remove excess Nutella from your hands. If you need to bake the cookies in batches, place the unused dough and Nutella back in the refrigerator/freezer until ready for next batch.