In a saucepan, heat the cream, milk, sugar and salt over medium heat; whisking to dissolve the sugar, approximately 3-4 minutes.
In a mixing bowl, whisk the egg yolks until creamy. Slowly pour 1 cup of the hot milk mixture into the egg yolk bowl, being sure to continually whisk to temper the eggs and ensure they do not cook.
Add the tempered egg yolk mixture back to the pan while whisking until it comes to a simmer.
Remove the pan from the heat, then add the vanilla extract and espresso.
Pour the ice cream base through a fine mesh sieve and chill completely, ideally overnight.
Churn in an ice cream maker according to the manufacturer's instructions.
Scoop half of the churned ice cream into a freezer-safe container then sprinkle with 1/2 cup of chocolate chips. Add the remaining ice cream to the container and using a spatula or spoon, incorporate the chocolate chips into the ice cream evenly. Top the ice cream with the remaining chocolate chips, cover with a lid and freeze for at least 4-5 hours until the ice cream is solidified and scoopable.