Place the milk, water, sugar in a pot and before it heats add the corn starch, the egg yolks, the vanilla and stir slowly until it thickens. If it gets too thick add a little milk.
Spread the biscuits in a pyrex tray after dipping them in brandy diluted with water.
Dissolve the cocoa powder into 1/4 cup hot water.
Incorporate half the custard.
Add the margarine into the rest of the custard and mix to melt (not over heat).
Have the two custards ready.
Spread the custard with the butter.
Spread another layer of biscuits dipped in diluted brandy.
Spread the chocolate custard.
Sprinkle with crumbled biscuits or ground walnuts.Place the sweet in the fridge for several hours.
