Heat the milk, cream, Baileys, vanilla seeds and pod in a saucepan.
Bring to a simmer and immediately remove from the heat and allow to infuse.
In a large bowl beat the yolks with the sugar.
Remove the vanilla pod from the infused cream, then gradually pour the vanilla cream into the egg mixture whisking continuously.
Return the custard to the saucepan and stir over a gentle heat until the custard coats the back of the spoon.
Serve in a warm bowl.