In a medium saucepan, combine the heavy cream and whole milk. Heat the mixture over medium heat until it reaches a gentle simmer. Remove from heat.
In a separate bowl, whisk the egg yolks until smooth. Slowly pour about half of the hot cream mixture into the egg yolks, whisking constantly to temper the yolks and prevent them from curdling.
Pour the egg yolk mixture back into the saucepan with the remaining cream mixture. Return the saucepan to low heat and cook, stirring constantly, until the mixture thickens and coats the back of a spoon. This should take about 5 to 7 minutes. Do not let the mixture boil.
Remove the saucepan from heat and stir in the vanilla extract.
In a separate bowl, whisk the dulce de leche until it becomes smooth.
Add the dulce de leche to the saucepan with the custard mixture. Stir well to combine until the dulce de leche is fully incorporated into the custard.
Cover and put in the fridge for at least two hours, but I would do overnight
Take out of the fridge and make it according to the manufacturer’s instructions. (I always use my Cuisinart Ice Cream Maker)*
Wow everyone by serving it immediately or store in an airtight container in the freezer for up to 2 weeks.