Easy Vanilla Slice

Ingredients:
1/2 cup custard powder
1/2 cup caster sugar
1 cup cream
2 cups milk
1 tsp vanilla essence
8 oz vanilla cookies (28 biscuits)
1 1/2 cups pure icing sugar
2-3 tbs passionfruit pulp

Directions:
Place the custard powder and caster sugar in a saucepan. Add enough of the cream to make a smooth paste.
Place the saucepan over a medium heat. Gradually add the rest of the cream and the milk, mixing until well combined. Stir constantly with a wooden spoon until the mixture boils and thickens. Remove from the heat. Stir in the vanilla essence. Cover the custard with plastic wrap. Cool.
Spread a heaped tablespoon of the cold custard on a crispbread. Top with another crispbread. Transfer to a tray. Repeat. Chill for 30 minutes.
Sift the icing sugar into a bowl. Add enough of the passionfruit pulp to make a thick icing. Spread each slice. Allow icing to set.