Make cherry jam; place cherries and sugar in a medium saucepan; cook, stirring, over medium heat until sugar is dissolved. Simmer for 12 minutes or until cherries are soft and jammy. Cool.

Lightly grease a 20cm x 30cm slice pan; line base and sides with baking paper, extending the paper 5cm over sides.

Put the water into the bowl of an electric mixer, sprinkle over the gelatine and stir to combine.

Place the sugar, glucose and extra water in a medium saucepan; cook, stirring, over low heat until sugar is dissolved. Bring to the boil. Add a sugar thermometer to pan; boil, without stirring, for 5-7 minutes or until temperature reaches 115°C or soft ball stage. To test if syrup is ready without a thermometer, drop a teaspoon of syrup into a glass of cold water. Gather syrup with your fingers – it should roll into a soft ball.

With mixer operating on high, gradually add the hot syrup to the gelatine mixture in the bowl, in a thin, steady stream. Add the vanilla and colouring, and beat for 12 minutes or until thick and fluffy.

Quickly spoon half the mixture into the prepared pan; spread with cherry Jjam. Cover with remaining mixture; smooth the top. Cover with lightly greased baking paper. Refrigerate for 2 hours or until set.

Sift icing sugar and cornflour into a bowl then sift lightly over a sheet of baking paper. Turn the marshmallow out onto the baking paper. Dust top and a knife with icing sugar mixture; cut into squares. You may need to wash and dry knife occasionally.