Marshmallows

Cooking ingredients

2 x 7g sachets powdered gelatine
450g/1lb caster sugar
2 tsp vanilla extract (or 1 tsp almond extract)
1 tbsp sunflower oil
50g/2oz icing sugar, plus extra for dredging
50g/2oz cornflour, plus extra for dredging
finely chopped pistachios, crystallised flower petals, or coloured caster sugar to coat (optional)