With a stand or handheld mixer, cream together softened butter and sugars until light and fluffy. Add in hazelnut butter, vanilla and milk.
In another bowl, sift together flour, soda, powder and salt.
On low, add flour mixture to mixer and stir until just combined. Add chocolate chunks and hazelnuts and stirr again until just combined. The batter may be slightly wet.
Let the batter rest at least one hour, covered in the fridge. I left it overnight with good results.
Preheat oven to 350 / 180. If your oven runs hot, then decrease the temperature at least 10 degrees.
Using a teaspoon create balls of dough and press down slightly. Space out on a baking tray to account for some spread.
Bake for 10 minutes, watching closely on the last few minutes. Take out when slightly brown on the edges only.
Optional: To get consistent sized round cookies, when you take out of the oven and when they are still on the baking tray, using a glass cup that is slightly larger than the cookie, place on top and over gently but quickly in a circular motion about 3-5 times.
Let cool completely.