Bring milk and cream to a slow simmer in a heavy saucepan.

In a bowl whisk egg yolks with sugar until pale. When the milk mixture comes to a boil, ladle a little into the egg yolks while whisking. This is tempering

Add this back to the simmering milk whisking constantly, add vanilla. Cook through until thickened.

Remove from heat. Serve warm over crumble cake or any other dessert. Enjoy. You can also refrigerate and enjoy cold