Step 1

Brush a 20 x 30cm (base measurement) lamington pan with melted butter to grease. Line the base and 2 long sides with non-stick baking paper, allowing sides to overhang. Place the biscuits in the bowl of a food processor and process until finely crushed. Add the butter and process until combined. Spoon the biscuit mixture into the prepared pan and press firmly over the base. Place in the fridge.

Step 2

To make the filling, combine the butter, egg yolks, sugar, lime rind and lime juice in a medium heatproof bowl. Place over a saucepan half filled with simmering water and cook, stirring, for 20 minutes or until the mixture thickens. Transfer to a large bowl. Set aside to cool slightly.

Step 3

Place the warm water in a small heatproof bowl and sprinkle over gelatine. Bring a saucepan of water to the boil. Remove from heat and place the bowl of gelatine into the hot water. Set aside for 3 minutes or until gelatine softens. Whisk with a fork until the gelatine dissolves. Stir the gelatine into the lime mixture. Set aside, stirring occasionally, for 15 minutes to cool.

Step 4

Use an electric beater to beat the cream until soft peaks form. Use a metal spoon to fold the cream into the lime mixture. Pour over the base. Top with raspberries and gently press into filling. Place in the fridge for 2 hours or until set. Cut into 8 pieces. Serve with cream.