Slice the vanilla bean in half and with the knife, carefully scrape the vanilla caviar and add it to the milk. Also add the vanilla pods to the milk. Let that simmer in low heat.
In a bowl, combine the eggs yolks and sugar. Whisk for a minute or so, until the mixture smoothens out.
Add the cornstarch and whisk the mixture again until the lumps smoothens out.
When the milk starts to bubble, that means it is boiling. Pour a little of the hot milk to the egg mixture and whisk it a few times.
Next, pour the egg mixture to the hot milk mixture and cook again in low heat, whisking it constantly.
When it starts to thicken, take it out of the heat and add the butter.
Mix it well with a whisk until the butter melts.
Carefully remove the vanilla bean pods, and put the cream in a bowl. Cover it with saran wrap, making sure the plastic touches the surface to prevent the cream's surface from creating a crust. Let it cool in the refrigerator.