Preparation:

1: Make the Biscuit Base

1. Prepare a 20 cm x 30 cm rectangular slice pan by lining it with baking paper, leaving an overhang on the sides for easy removal later.
2. In a large bowl, combine the crushed biscuits, melted butter, and sweetened condensed milk. Mix until the crumbs are well coated and resemble wet sand.
3. Press the mixture firmly and evenly into the base of the lined tray using the back of a spoon or the base of a measuring cup.
4. Chill in the fridge for at least 30 minutes while you prepare the next layer.

2: Prepare the Jelly-Marshmallow Layer

1. In a large mixing bowl, combine the jelly crystals and powdered gelatine.
2. Pour in the boiling water and stir continuously for 2 minutes, until completely dissolved.
3. Add the caster sugar and continue stirring until fully dissolved.
4. Pour in the cold water and mix again until incorporated.
5. Let the mixture sit at room temperature for 15–20 minutes until it cools slightly. You want it cool but still liquid, not set.

Note: Pouring warm jelly mixture over the biscuit base too soon can cause it to seep through—cooling is essential.

3: Pour and Chill the Jelly Layer

1. Once cooled, carefully pour the jelly mixture over the chilled biscuit base.
2. Transfer to the fridge and chill for 2–3 hours, or until the jelly layer is completely set and firm to the touch.

4: Add Marshmallow Topping

1. Once the jelly layer is set, evenly scatter the mini marshmallows over the top of the slice.
2. Gently press them into the jelly to ensure they stick but don’t sink in.
3. Sprinkle the top with shredded coconut and pink and white sprinkles for extra colour and texture.
4. Return to the fridge for an additional 30 minutes to allow the toppings to set in place.

5: Slice and Serve

1. Using the baking paper overhang, lift the slice out of the tray and place on a chopping board.
2. Use a sharp knife dipped in hot water and wiped dry to slice into 12–16 squares.
3. Wipe the knife between cuts for cleaner edges.