How to cook
First, dissolve the starch in 1 cup milk, put the rest of it to heat up on the stove with the sugar. Then add the vanilla and butter to it.
Beat the egg yolks separately from the whites, then pour the yolks in a thin trickle to the milk.
Carefully pour this mixture into the starch while beating nonstop on the stove until thickened. Remove the ready vanilla cream from the heat and leave it to cool a bit.