Preheat oven to 180C.
Place whole hazelnuts on a baking tray and toast in oven for 10 minutes, until they are lightly golden and fragrant.
Rub the hazelnuts in a clean tea towel to remove most of the skins. Let them cool completely.
Pulse the hazelnuts in a food processor until they are coarsely chopped.
Reduce oven temperature to 150C.
Beat the egg whites with a pinch of salt until very stiff peaks form.
Gently fold in nuts and the coconut sugar. Do this with a metal spoon in batches.
Line 2 trays with baking paper and spoon heaped teaspoons of the cookie mixture onto the trays, leaving 3cm between each one.
Bake for 30 minutes, until the biscuits are lightly golden. Let them cool on the trays.
