1. Crush the hazelnuts in the blender (check if there are any hazelnuts on the sides of the blender while you do this; if so, stop and peel it off with a utensil and throw it down).
2. Add the rest of the ingredients and blend again until you get a homogeneous consistency (in this step, also check if there is any mixture sticking to the walls of the bathtub).
3. Transfer it to a container with a lid and store in the fridge.