Cooking oil spray, to grease
200 g packet lattice biscuits
⅔ cup custard powder
4 cups milk
¾ cup caster sugar
Finely grated zest and juice of 2 lemons
1 cup icing sugar mixture
1 tbsp passionfruit pulp
Grease a 20cm square cake tin with cooking oil spray. Line base and sides with baking paper, leaving paper extending 2cm above tin. Line base of prepared tin with 9 biscuits, in a single layer.
- Put custard powder and 1 cup of the milk in a medium saucepan and whisk until combined. Whisk in sugar and remaining milk. Put over a medium-high heat and cook, stirring with whisk, for 5 minutes or until custard is very thick. Remove from heat and stir in lemon zest and juice. Return to heat and cook for a further 2 minutes, stirring continuously. Remove from heat. Pour over biscuits in tin. Top with a second layer of 9 biscuits. Refrigerate for 2 hours or until set firmly.
- To make icing, put icing sugar and passionfruit in a bowl and stir until smooth. Spoon icing over slice. Refrigerate for a further 1 hour or overnight, if convenient, until icing sets. Using biscuits as a guide, slice into 9 squares to serve.