Spread the hazelnuts on a tray in a single layer and roast for 10 mins, then tip into a blender with a tsp of the oil and blitz until the oils release and you have a nut butter. It will take several minutes, stopping regularly to scrape down the sides.
Add the remaining oil and blitz through, then add the remaining ingredients and blitz briefly until just combined. Taste.
If you like, you can add more cocoa at this stage to make it a deeper chocolatey brown. Just pulse briefly to avoid over working it.
Transfer to a clean, lidded jar and store in the fridge for up to a month.
To make the pancakes:
Sift the flour, salt and icing sugar into a bowl and make a well.
Whisk the eggs and milk together, then pour into the flour and whisk until fully combined.
Next, whisk in the melted butter followed by the bicarbonate of soda.
Warm a pancake pan over a medium heat with a dot of butter, then ladle in enough batter to just cover the pan in a thin layer, swirling to distribute.
Quickly sprinkle with a tablespoon of oats before the batter has time to set.
Flip the crêpe and cook on the other side until golden. Tip on to a plate.
Repeat with the rest of the batter, placing a square of greaseproof between each one.
To serve, spread the crêpes with the chocolate hazelnut spread as generously as you like, then roll up and serve.