Bring the milk, the split vanilla pod and the spilled marrow to a simmer in medium heat. Then turn off the heat and let it infuse for fifteen minutes.

Put the egg yolks, cornstarch and sugar in a bowl and beat everything until the mixture becomes pale.

Bring the vanilla milk back to the boil. Beat a third of the milk through the egg mixture. Then add the rest of the milk and mix everything well. Pour the sauce back into the pan and slowly heat with a spatula while stirring vigorously. Always scrape well over the soil to prevent lump formation. Remove the pan from the heat when the sauce starts to bind. Add the butter and beat until all the butter has been absorbed.

Pour the cream onto a piece of plastic wrap and wrap it well so that it does not dry out. Allow to cool in the refrigerator.