Biscuit custard surprise

Ingredients
Marrie biscuits crushed 2 cups
Melted butter 4 ounce
Vanilla custard prepared 2 cups
Mango cubes 2 cups
Chocolate sauce as required
Grated chocolate ½ cup
Method
Crush biscuit, mix with melted butter, press into a shallow pyrex dish, spread with prepared custard, top with mango cubes, drizzle chocolate sauce, serve chilled.