Note: Make sure to freeze the base of your ice cream maker overnight before making this recipe.
- In a medium saucepan, slowly whisk the cornstarch into 1 cup cold whole milk, then whisk in the sugar and instant espresso. Apply medium heat and heat for 4 to 6 minutes, whisking frequently, until nearly simmering and the mixture thickens.
- Remove from the heat. Stir in the remaining 1/2 cup whole milk, heavy cream, salt, and vanilla extract.
- Transfer the mixture to a large metal or glass bowl. Place the bowl in a smaller bowl of ice water for 1 hour, making sure not to splash any water into the ice cream. Alternatively, simply place the bowl in the refrigerator and wait for 3 to 4 hours or until the temperature drops to 40 degrees Fahrenheit.
- Churn according to your ice cream maker instructions, about 25 minutes for soft serve consistency.
- Transfer the churned ice cream into a loaf pan or storage container. Place the container in the freezer and freeze for at least 2 hours (or overnight), which “ripens” the ice cream and creates the hard ice cream texture. Store in a loaf pan with a parchment sheet over the top or a sealed container in the freezer for up to 2 weeks.