In a medium bowl combine ground hazelnuts, coconut flour, spelt flour, baking powder and salt. Whisk to blend and set aside.
In a large bowl whisk together butter and the two kinds of sugar until well combined. Add egg and vanilla extract and whisk shortly until the mixture gets thicker and becomes uniform.
Gradually add the dry ingredients, whisking gently with a wooden spoon, until just absorbed.
At the end add the chopped hazelnuts and the chocolate chips. Whisk very carefully to distribute around the batter but do not overmix.
Make a ball out of the dough. Cover the bowl with the dough with plastic wrap and let it stay in the fridge for 30-60 minutes.
Preheat oven to 180 degrees C (350 degrees F). Line 2 large baking tins with sheets of parchment paper or silicon mats.
Make small balls out of the dough, approximately as big as medium apricots. Place them not very close one next to another on the prepared pans.
Bake 10-12 minutes on the top rack of the oven, until the cookies get brown on the edges. If they look too pale, you can switch the oven to top heat only for few minutes.
Let the cookies cool and then serve them with an ice cream scoop on top.