Preheat Oven & Bake Pastry – Preheat the oven to 180°C (fan-forced). Line baking trays with parchment paper.

Prick the pastry sheets with a fork, cover with another sheet of parchment, and place a baking tray on top as a weight.

Bake for 20-25 minutes until golden. Let cool completely.

Trim the pastry to fit a 20cm square baking tin. Grease and line the tin with parchment paper, allowing overhang.

Place one pastry sheet into the tin and set aside.

Make Custard – In a saucepan, mix custard powder with ¼ cup of milk until dissolved. Add the remaining milk and sugar.

Heat over medium, whisking continuously for 5 minutes until thick. Once boiling, whisk for another 2 minutes until very thick.

Cover custard with plastic wrap and cool for 20 minutes.

Spread the cooled custard over the pastry in the tin. Top with the second pastry sheet.

Prepare Icing – Sift icing sugar into a bowl. Add food coloring (if using).

Add water 1 tbsp at a time, stirring until a smooth, spreadable paste forms.

Spread icing over the slice and refrigerate for at least 3-4 hours (overnight is best).

Slice & Serve – Use a serrated knife to gently cut through the top pastry, then a larger knife to press down and cut into slices.