Step 1

Line base and sides of a slice tin (20 x 30 cm) with baking paper. Line base of tin with biscuits, glossy side down, trimming biscuits to fit, if needed. Set aside.

Step 2

Place cornflour and sugar into mixing bowl and mill 3 sec/speed 5.

Step 3

Add milk, eggs and vanilla and mix 5 sec/speed 4.

Step 4

Scrape down sides of mixing bowl with spatula and cook 10 min/90°C/speed 3.

Step 5

Scrape down sides and base of mixing bowl with spatula and cook 5 min/90°C/speed 3 or until custard thickens. Spread custard filling evenly over biscuit base. Top custard filling with another layer of biscuits, glossy side down and trimming to fit if needed. Set aside to cool for 30 minutes. Cover with plastic wrap and place into refrigerator (for a minimum of 3 hours or overnight) until custard is firm. Clean and dry mixing bowl.

Step 6

Place sugar into mixing bowl and mill 1 min/speed 9.

Step 7

Add egg white, lemon juice and water and mix 10 sec/speed 7. Transfer 2 tablespoons of icing into a small bowl. Add a drop of red food colouring and stir to combine. Transfer into a piping bag fitted with a thin nozzle and set aside.

Step 8

Working quickly, spread remaining plain icing over top of biscuits. Working quickly, pipe red icing lines at intervals (1.5 cm) horizontally across slice. Before icing sets, use a wooden skewer to draw a line in intervals (1.5 cm) vertically through lines of red icing. Place into refrigerator for a minimum of 1 hour to set. Cut into 16 squares to serve.