Step 1: Grease and line a 20cm square cake tin with baking paper, leaving plenty of paper overhanging to make it easy to lift the finished slice out.

Step 2:In a food processor, blitz biscuits into a fine crumb. Add melted butter and melted Golden Gaytime, and blitz to combine. Pour into prepared tin and use the back of a large metal spoon to press into an even layer. Refrigerate while you prepare the filling.

Step 3:In a small saucepan, place 1/4 cup cream and the Caramilk chocolate broken up into squares. Stir over very gentle heat until melted and smooth. Dissolve 1 teaspoon gelatine in 1 tablespoon of boiling water, and whisk into melted Caramilk mixture. Separate eggs. Whisk yolks into melted chocolate mixture. Set aside to cool.

Step 4: Whisk egg whites until stiff. Fold into cooled Caramilk mixture. Pour over biscuit base in tin and smooth the top. Return to fridge to set while you prepare the next layer.

Step 5: In a small saucepan, place 1/4 cup cream and white chocolate melts. Stir over very gentle heat until melted and smooth. Dissolve 1 teaspoon gelatine in 1 tablespoon of boiling water, and whisk into melted white chocolate mixture. Allow to cool, then add remaining 180ml cream and whisk until thick and smooth, being careful not to over whip. Pour over Caramilk layer in tin and smooth the top. Refrigerate for 30 minutes to set.

Step 6: In a small metal bowl, place dark chocolate and oil. Place over a small saucepan of simmering water and stir to melt. Alternatively, melt in short bursts in the microwave. Drizzle over slice and crumble over Butternut Snap biscuits. Allow dark chocolate to set, then lift slice out of tin using overhanging baking paper. Use a hot knife to slice into squares to serve.