Step 1

For marshmallows, stir glucose, 100gm sugar and 60ml water in a small saucepan over medium-high heat until sugar dissolves, bring to the boil and cook until syrup reaches 118C on a sugar thermometer (4-5 minutes). Meanwhile, whisk eggwhite and a pinch of salt in an electric mixer until soft peaks form, then gradually add remaining sugar and whisk until glossy. When syrup reaches 127C (3-4 minutes), remove from heat. Squeeze excess water from gelatine and stir into syrup. Whisking on low-medium speed, gradually add syrup to meringue, then whisk on high until thick and cooled to room temperature (10-15 minutes). Transfer to a piping bag with a 1cm plain nozzle and pipe 8cm-diameter rounds on a tray lined with baking paper and stand until set. Marshmallows will keep in an airtight container for 5 days.

Step 2

Beat ice-cream in a large bowl with a wooden spoon to soften, then fold in jam, transfer to a container and freeze until firm (3-4 hours).

Step 3

For brown sugar biscuits, preheat oven to 180C. Beat butter and sugar until pale and creamy (2-3 minutes). Scrape down sides of bowl, beat in egg and stir in dry ingredients. Refrigerate until firm, then roll out on a lightly floured surface to 3mm thick. Cut out 8cm-diameter rounds. Place on a baking tray lined with baking paper and bake until golden on the edges (5-6 minutes). Cool on trays and store in an airtight container. Biscuits will keep for 2-3 days.

Step 4

For choc-fudge sauce, stir chocolate, sugar, glucose, cocoa, butter, 1 tsp sea salt and 170ml water in a saucepan over medium-high heat until smooth and combined, then bring to the simmer and cook until sauce has a light syrup consistency (4-5 minutes). Set aside.

Step 5

To serve, place half the biscuits on serving plates, top each with a marshmallow round and scoop of ice-cream, drizzle with warm choc-fudge sauce, and sandwich with remaining biscuits.