Line a 1kg loaf tin with clingfilm. To make the cocoa nib praline, spread the cocoa nibs out on a baking sheet lined with silicone paper or lightly oiled foil.
Gently heat the caster sugar in a heavy frying pan until the sugar melts, swirl the pan gently every now and then to encourage the sugar to melt evenly but don’t stir or the sugar could crystallise.
When the sugar has turned to liquid and then a deep amber-coloured caramel, pour it quickly over the cocoa nibs. Cool completely then break into shards.