Heat the whole milk, heavy cream, sugar, and salt over medium until the sugar dissolves.
Whisk the egg yolks in a bowl.
Slowly add the cream and milk mixture to the beaten egg yolks and keep whisking until blended.
Put them back into the saucepan while whisking until it comes to a simmer.
Remove the pan from the heat, let cool for one minute, and add the vanilla extract.
Let it rest while making two shots of espresso.
Add the espresso shots, mix well, and strain before chilling in the fridge.
Pour the custard into an ice cream maker before transferring it into an air-tight container in the freezer. Give it around 4 hours to freeze.