Step 1
Grease a 20 x 30cm slice pan and line with baking paper, allowing the 2 long sides to overhang.
Step 2
Break the biscuits and place into a food processor and process until crushed. Pour in the butter and process until combined. Transfer to the prepared pan and use the back of a spoon to press firmly into the base. Place in the fridge for 30 minutes or until firm.
Step 3
Place the cream and Sherbies in a heatproof bowl set over a saucepan of simmering water (do not allow the bowl to touch the water). Cook, stirring often, for 10 minutes or until the Sherbies have completely melted. Pour the mixture into a separate bowl and place in the fridge, stirring occasionally, for 20 minutes or until the mixture has cooled to room temperature.
Step 4
Place 2 tablespoons of water in a small microwave-safe bowl and sprinkle over the gelatine. Set aside for 2-3 minutes to soften. Microwave on HIGH for 20 seconds or until hot. Use a fork to whisk and dissolve the gelatine.