Combine all ingredients in a medium saucepan on medium-low heat. Stir until the custard begins to form, at about 170 degrees Fahrenheit. The mixture will become thicker and stick to the back of the spoon. You will be able to draw a clean line through the mix on the back of the spoon.
Transfer the custard into a heatproof bowl and refrigerate until the mix is at 40 degrees Fahrenheit. When the mixture has cooled, use an ice-cream maker, freeze according to the maker's instructions.
Freeze the mixture overnight for a firmer ice cream. Enjoy!
Method & recipe adapted from this recipe on Serious Eats: http://www.seriouseats.com/recipes/2014/05/vanilla-frozen-custard.html