Caramel Custard Slice

Step 1: Grease an 18cm (base measurement) square cake tin with cooking oil spray and line base and sides with baking paper, extending paper 1cm above tin.

Step 2: Line base of prepared tin with 9 biscuits, in a single layer, shiny side down.

Step 3: Put butter, brown sugar and syrup in a medium saucepan and bring to the boil and continue to boil vigorously, stirring constantly for 4 minutes and then remove from heat and whisk in condensed milk and return to the stove over medium heat and cook, stirring constantly, for 8 minutes or until very thick and slightly deeper caramel in colour and then remove from heat.

Step 4: Put custard powder and 250ml of the milk in a large heatproof bowl and whisk until combined, then pour in hot condensed milk mixture, whisking until smooth.

Step 5: Return mixture to saucepan over medium heat and pour in remaining milk and cook, stirring constantly with a whisk, for 5 minutes or until very thick, then continue to cook, stirring vigorously for a further 30 seconds and then spoon on top of biscuits in tin.

Step 6: Top with a second layer of 9 biscuits, shiny side up and refrigerate for 2 hours or until set firmly.

Step 7: To make icing, put icing sugar, cocoa and water in a bowl and stir until smooth.

Step 8: Spoon icing over slice and refrigerate for a further 1 hour or overnight, if convenient, until icing sets.

Step 9: Using biscuits as a guide, slice into 9 squares to serve.