125 ml milk  —  preferably whole milk
125 ml cream
3 large egg yolks
60 g sugar
½ vanilla bean

Pour the milk and cream in a thick-bottomed saucepan. Split the vanilla bean lengthwise and scrape out the seeds. Add the seeds and the bean halves in the saucepan. Bring the mixture almost to the boil and simmer for about 20 minutes, without letting it boil. Stir every now and then to prevent a skin forming on the surface.

Beat the egg yolks and sugar until pale and fluffy, continue beating and gradually add the hot milk mixture. Pour the mixture back in the pan and heat gently, stirring continually, until the sauce thickens and reaches the temperature between 70 - 80 °C. Do not let the sauce reach the boiling point as it may coagulate.

Pour the thickened sauce through a fine sieve to remove the pieces of vanilla bean and any possible lumps of coagulated egg. Serve the sauce warm or cold. If served cold, place the saucepan in a cold water bath and beat the sauce until it has cooled down. It will further thicken as it cools.

Serve the sauce with baked apples, apple or rhubarb pie, or other fruit or berry pies and desserts.