Mojito Marshmallows

Prepare the tin by spraying lightly all over with non-stick cooking spray or brushing with a little vegetable oil. Add a tablespoon of the icing sugar and cornflour coating and tap around the tin to coat the base and sides evenly. Set aside.

Make the mojito flavouring by mixing the lime juice and most of the zest (keep a little for decoration), rum and chopped mint in a small bowl.

Prepare a batch of classic marshmallow mixture: Add the gelatine sheets one at a time (to prevent them clumping together) to a shallow bowl of cold water and set aside to soften. Pour the egg whites into the clean bowl of a food mixer and whisk until they hold stiff peaks. Turn off the mixer while you make the syrup. Put the sugar and water into a heavy-based pan and warm over a low heat, stirring until the sugar has completely dissolved. Stand a sugar thermometer in the pan, increase the heat to medium-high and bring up to the boil. Allow to bubble away, undisturbed, for around 15 minutes until the temperature reads 122°C. This is what is known as the ‘firm ball’ stage. If you don’t have a sugar thermometer, drop a teaspoon of hot syrup into a glass of cold water. It should form a firm ‘toffee-ish’ ball that holds its shape. Remove the thermometer from the pan and leave it on a chopping board or plate to cool down.

With the mixer set on low speed, start to beat the egg whites once more. Add the hot syrup in a steady trickle, mixing continuously as you pour. As soon as all the syrup has been added, increase the speed to maximum. Remove the leaves of gelatine from the cold water, giving them a little squeeze dry, then drop them into the mixer as it is turning and whisk on high speed for 10 minutes. The mixture should be thick, shiny, and just about pourable.

Once the mixture is thick and glossy, add the mojito flavouring to the mixer and whisk for a further minute or so until it is completely combined. Scrape into the prepared tin, levelling with the flat of a table knife. Dust the surface liberally with more of the coating and leave to set for 4–6 hours (or overnight).

Once the marshmallow has set, turn out on to a chopping board that you have dusted with a little more coating. Cut into squares, tossing in a little more coating as you go. Decorate with the reserved zest.