Put the eggs, the sugar and the Maizena in a bowl.
Mix vividly but without making the mixture turn white.
Heat the milk with the vanilla extract in a pot until it boils.
Add a third of the milk infused with vanilla to the mixture, mix well.
Once it all seems incorporated, add the rest of the milk and mix again.
Add back everything on a pot with high heating and mix thoroughly.
As soon as the cream starts to thicken, remove the pan from the heating and add the butter.
Mix until you have a homogenous cream.
Pastry cream can be conserved in a fridge under cellophane wrapping.
