1 cup sugar
125 ml custard powder
Mix the sugar and custard powder.
Add 1 liter milk and mix well.
Add 80ml butter and 20 ml vanilla essence, microwave for 10 min on high.
Whisk the mixture every 2 minutes with a metal whisk.
The custard is perfect when the mixture makes patterns when whisking. 
Line your bowl with cream crackers.
Pour the custard mixture over the cream crackers and add another layer of cream crackers on the custard mixture. 
Let it cool.
Mix 1 cup icing sugar with 1 tablespoon boiling water and some lemon juice.
Spread the icing mixture over the crackers, let it set and enjoy!