Melt 500 g (1 lb 2 oz) sugar very slowly in a copper bowl and cook it to a light caramel colour. Alternatively, the sugar may be cooked in the ordinary way and stopped when it reaches the required temperature. Mix in 500 g (1 lb 2 oz) very dry whole almonds or hazelnuts, or equal quantities of each, according to requirements.
Pour on to an oiled marble slab and allow to go cold. Crush in the mortar then pass through a fine sieve; keep in a tightly closed container in a dry place if required for future use.