A little melted dark chocolate or a writing icing pen
Put the egg whites in the bowl of a stand mixer with the whisk attachment fitted and whisk to stiff peaks – when you lift out the beaters the egg white forms peaks that don’t flop over at the tip.
Mix the caster sugar with the icing sugar, then add to the egg whites 1 tbsp at a time, whisking back to stiff peaks after each addition. Continue until all the sugar is incorporated, then transfer the mixture to a piping bag.
Pipe the ghosts on to a baking sheet lined with non-stick baking paper – it’s fun to make a range of sizes, then bake at 120C/100C fan/gas ½ for 1 hour 30 minutes until crisp.
Cool completely, then pipe faces on to the ghosts with a little melted dark chocolate or a writing icing pen.