Ingredients:
2 1/2 tbsp vegetable gelatine
250g sugar
240ml light corn syrup (golden syrup)
120ml cold water
120ml water at room temperature
1/4 tsp salt
2 tbsp vanilla extract
cornflour for dusting
Method:
Combine the gelatine and cold water in the bowl of a mixer with a whisk attachment and allow to stand for half an hour. When the time is up mix the sugar, corn syrup and the remaining water in a saucepan. Stir over low heat until the sugar has dissolved and a syrup has formed. Bring gently to a boil and cook to the Hard Ball stage (118–121°C as measured on a confectioner's thermometer). Remove from the heat then slowly and carefully pour the syrup into the gelatine mixture. Best the mixture at high speed until thick, white and tripled in volume (this will take about 15 minutes).
Add the vanilla and beat just long enough for it to be incorporated. Dust a baking dish (about 20 x 30cm) with cornflour and pour-in the marshmallow mix. Wet your hands and pat the mixture to smooth-out the top then dust with more cornflour.
Leave to stand, uncovered, over night. The following morning turn out onto a board and cut into pieces with a hot knife. Dust these pieces with more cornflour before storing.