Make the Nutella filling: scoop heaped teaspoons of Nutella (or use a piping bag, fill with the Nutella, and pipe 1.5" blobs of Nutella) onto baking sheet lined with parchment paper. I use 1 cup of Nutella to make about 22 portions (I like to make a bit more than I need just in case). Place baking sheet in the freezer and let it chill until solid, 30-60 minutes.
Divide dough into 20 equal balls, each weighs 30 grams, the size of 1.5 tablespoons (I use this ice cream scoop). Press the balls out slightly flat. Take the chilled Nutella out of the freezer. Place one round of Nutella in the middle of each piece of dough and fold the dough around it to form round and sealed balls. Work quickly so the Nutella won’t melt (if it does, put it back into the freezer). Place balls on baking sheets lined with parchment paper. Chill in the fridge for 15-30 minutes before baking.
Store cookies at room temperature in an airtight container for up to 3 days or in the refrigerator for up to 1 week. Cookies can be frozen for up to 2 months, then thawed at room temperature for 2 hours or in the fridge overnight before using.