Line a 25 cm x 35 cm deep oven tray with baking paper and spray with non-stick cooking spray. Get all the ingredients ready for the marshmallows. Once you start mixing, you have to work fast.
First make the caramel by placing the castor sugar and 1 tbsp water in a small saucepan over low heat. Leave to dissolve while brushing off any sugar crystals that form on the sides of the pan with a clean pastry brush dipped in hot water.
Turn up the heat and cook until the sugar caramelises.
Add the butter, cream and salt and whisk with a wooden spoon until combined. Set aside to cool.
To make the marshmallows, sprinkle the gelatine over 250 ml water in a small bowl and leave to sponge.
Heat the sugar, glucose and the 160 ml water in a small saucepan over low heat. Leave to dissolve while brushing off any sugar crystals that form on the sides of the pan with a clean pastry brush dipped in hot water.
Turn the heat up and cook the sugar to 120°C on a sugar thermometer.
Melt the gelatine on the defrost setting of the microwave for 1 minute (do not let it boil). Pour into the bowl of an electric mixer with the 250 ml hot water. Mix on the slowest setting of the mixer. Add the warm sugar syrup to the gelatine mixture while mixing. Turn up the speed and whisk the mixture until it is white and fluffy (this can take a while).
Turn the mixture out into the prepared tray. Drizzle 125 ml of the cooled, salted caramel over the marshmallow mixture and marble it through. Leave to set for 2 hours. Turn over when set and cut into fingers or squares.
Mix the icing sugar and corn starch in a tray, roll the marshmallows in this mixture and keep in an airtight container.
Recipe reprinted with permission of Bread n Butter