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 whizz 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.
*If you buy blanched hazelnuts you can use them straight from the packet. If you can't get blanched 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.
You can make this hazelnut 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) though be careful not to overblend. High speed blenders are very powerful so it's easy to overblend and turn the hazelnuts into liquid rather than nut butter.
You can either melt the chocolate in a microwave or by placing it in a bowl over a pot of gently simmering water (without the bowl touching the water) and slowly melting stirring often.
Use a clean and dry bowl and spatula for melting the chocolate (ensure it doesn't come into contact with moisture).
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).
Keep the spread in a jar for up to a week. The consistency of this hazelnut chocolate butter improves over time and gradually becomes smoother and creamier. If you keep it in the fridge (I keep mind in a cupboard) it will solidify but this is easy to fix by popping in the microwave for a few seconds before using.
Serving: delicious on toast, with or without sliced banana, on waffles, with crepes, breadsticks or on its own as a high protein snack. Try blending it with natural yogurt and banana and make your own homemade 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.