How many eggs do you need to make 1 liter of egg custard?

1litre of milk, 3pc of whole eggs, 1pc of egg yolk, 110g of sugar, 80g of Elsay powder or 100g of corn starch, 1pod of vanilla

mix the eggs,sugar and the cream powder with a whisk. open the vanilla, take the seeds out and place into the milk. add the stick as well. boil the milk. take some hot milk to the egg mixture, mix it, then pour back to the hot milk. cook it not less than 5 minutes and keep stirring with a whisk. ready. if too thick add some more milk. I use this recipe for base custard cream for mille feuille...