Folonomo's cacao nib rocks

Preheat oven to 190C and line 2 large oven trays with baking paper. Whisk eggwhite in an electric mixer until foamy (30 seconds to 1 minute). Gradually add caster sugar, whisking continuously, until stiff peaks form and sugar dissolves (5-7 minutes). Fold in almond meal, then gently fold in cacao nibs and vanilla. Transfer to a piping bag with a large plain nozzle (about 1.3cm) and pipe 5cm flat rounds onto baking trays with a 2cm gap between each. Smooth peaks with the back of a spoon and bake on middle and lower shelves until lightly coloured (15-18 minutes), then swap trays, reduce heat to 180C and bake for a further 8-10 minutes; to test they're done, break one in half – it should be evenly golden inside. Set aside to cool and crisp (15-20 minutes). Store in an airtight container for up to a week.