Raspberry ripple marshmallows

Lightly brush the inside of a 27x18x4cm tin with vegetable oil. For the coating, mix the icing sugar and cornflour in a large roasting tin. Sieve a little of this mixture into the prepared tin, then tilt and tap it to cover the base and sides, especially in the corners. Do this over the roasting tin to limit mess, then tap the excess back into the tin and set aside.

Heat the granulated sugar and 250ml cold water in a large, heavy-based saucepan over a low heat. Once the sugar has completely dissolved, increase the heat to high and boil hard, without stirring, for 10 minutes, or until a sugar thermometer reaches 115ºC. The syrup will be clear but will have thickened and the bubbles will have increased in size.

Meanwhile, put the gelatine in a bowl of room temperature water to soften. In a separate bowl, beat the egg whites with an electric whisk (or preferably using a freestanding mixer) until stiff. Tip away the water from the gelatine and wring it out thoroughly to remove any excess water. Return the gelatine to the empty bowl.

As soon as the sugar syrup is ready (see above) add half of it in a slow, steady stream to the egg whites, beating fast as you go. Stop at the halfway mark and add the gelatine to the pan of sugar syrup – it will sizzle, then quickly become jelly-like. Swish the pan to melt it all before continuing to add it to the egg whites as before. Add the raspberry flavouring and ½ the raspberry powder. Whisk for a further 10 minutes on maximum speed.

Add the remaining raspberry powder to one side of the marshmallow mixture. Using a large spatula, gently fold the mixture over the powder once or twice to marble it, before pouring into the prepared tin. Cover and place in the fridge to cool for 2 hours until set.

To cut the marshmallow, dip a round-bladed knife into boiling water and cut the set mixture into cubes. Drop each sticky cube into the icing sugar and cornflour mixture and turn until well coated. Tap off the excess before putting them into gift bags or boxes.