Tear each gelatine sheet into  three pieces, put them in an electric mixing bowl, then pour over 220 grams water and let the gelatine soften.

Put the sugar, glucose and remaining 100 grams water in a medium saucepan and bring to the boil. Test the temperature with a sugar thermometer. Once it reaches 116C, remove it from the heat.

Turn the mixer on to a slow setting and carefully drizzle the hot syrup into the bowl, making sure it hits the gelatine. After pouring in the syrup, increase the mixer speed to high and mix until it has tripled in volume and cooled. Add the vanilla essence and mix for a minute.

If you are making my recipe for soft chocolate pie, line one 22 x 22 x 6-centimetre container with plastic wrap, pressing it in tightly against the edges. Reserve half the marshmallow mix for the pie topping. Spoon the rest into a piping bag and pipe it into the container in lines so you end up with a solid slab of marshmallow.

If you are not making the pie, repeat in another container of the same size. Let it set for 30 minutes at room temperature. Sift the icing sugar and cornflour into a bowl. Cut each marshmallow slab into five-centimetre squares and roll in the icing sugar mixture. Store in an airtight container in the pantry.

TIP
For flavoured marshmallow, try adding half a teaspoon of rose water when you pour over the water to soften the gelatine.