Vanilla marshmallows

1.Combine 175gm caster sugar, glucose and 100ml water in a saucepan. Cook over medium-high heat until mixture reaches 118C on a sugar thermometer (3-5 minutes). Meanwhile, squeeze water from gelatine and melt in a bowl placed over a saucepan of simmering water (2-4 minutes). When syrup reaches 118C, start whisking eggwhites in an electric mixer until soft peaks form, then gradually add remaining caster sugar. Meanwhile, continue cooking syrup until it reaches 127C (4-8 minutes). Add gelatine and vanilla to syrup, then, whisking continuously, gradually add to eggwhite mixture. Whisk until cooled and thick (10 minutes), transfer to a 2cm-deep, 15cm x 25cm tray lined with baking paper, smooth top and refrigerate to set (1-2 hours). Cut into squares and dust with snow sugar just before serving.