Place the chocolate pieces in a bowl and heat up in the microwave until almost completely melted. Stir until smooth.
Place the hazelnuts in a blender and blitz until the mixture thickens but is not silky smooth. If you are using a high speed blender do this on a very low speed (it should take only about a minute).
Add the melted chocolate, cocoa and powdered sugar into the blender and whiz briefly just to combine.
Transfer the spread into a jar and chill before using. If you keep it in the fridge too long and the spread solidifies simply microwave it for a few seconds and give a good stir to loosen the consistency.
Store in a cool place for up to 5 days.
You can make this spread in a food processor or high speed blender. I like to use the latter as it's quick. Blend the mixture on low (ignore the 'nut' button if your blender has got one). High speed blenders are very powerful so it's easy to overblend and turn the hazelnuts into liquid rather than nut butter.
If you can't get skinned hazelnuts you can remove the skin yourself by roasting the hazelnuts on top of a baking sheet in a single layer at 180 C for 15 minutes. Remove from the oven, wrap the hazelnuts in a towel and rub until most of the skin has come off.
If using a high speed blender melt the chocolate before making the hazelnut butter (it only takes a minute to make the butter). If using a food processor melt the chocolate about half way through making the butter (it will take several minutes to make).
Store the spread in a jar for up to a week. The consistency of this spread improves over time and gradually becomes smoother and creamier. If you keep it in the fridge (I keep mine in a cupboard) it will solidify but this is easy to fix by popping in the microwave for a few seconds before using.
Serving suggestions: On toast, on waffles, with crepes or on its own as a healthy, high protein snack. Try blending it with natural yogurt and banana and make your own homemade flavoured yogurt.
Freeze for up to 3 months.
Total Time refers to making the spread using a high speed blender. It will take longer to make the spread in a food processor.