Put the sugar and vanilla in the milk to boil.
Beat the eggs.
Beat the flour with water to a sludge (medium thick) and add it to the beaten eggs.
Add the mixture to the milk and stir nonstop until thickened.
Separate the prepared cream into 2 containers, color one of it with the cocoa. Distribute into glasses.
Pour the yellow and brown creams in together.
You can put biscotti or other small biscuits in the middle.