In a small saucepan, bring cream and milk to a simmer. Take off heat then stir in a pinch of salt and vanilla paste. Keep warm.

Whisk yolks with sugar until smooth. Slowly add hot cream mixture to the yolks, whisking continuously. When completely smooth, add back to the saucepan then place over low heat. Stir using a wooden spoon until mixture begins to thicken. The sauce is done when it leaves a path on the back of the spoon when you draw your finger through it. Do not let the sauce boil or you will have scrambled yolks!

Strain sauce into a bowl and cool. Cover and refrigerate at least 30 minutes.