Boil milk and sugar
Mix custard powder, cocoa with evaporated milk and add in boiling milk
Let it boil kip on stirring to avoid lumps, til it thickens
Remove from flame and cover with lid
Crush digestive biscuits to crumbs

Place 6-7 dessert glasses on wrking table put 2 tbsp of biscuit crumbs in each glass
pour 2 tbsp of choc custard
Repeat once or 2 more times
Top up with choc shavings or chopped kitkat
Chill in fridge