Prepare the Ice Cream Base:
Combine heavy cream, milk, sugar, and salt in a medium saucepan. Heat over medium heat until bubbles form at the edges, but do not let it boil.
In a separate bowl, whisk the egg yolks. Slowly add 1 cup of the warm cream mixture to the yolks, whisking constantly to temper the eggs.
Return the egg mixture to the saucepan and cook over medium-low heat, stirring frequently, until the mixture thickens and coats the back of a spoon.
Strain the mixture through a fine-mesh sieve to remove any lumps. Chill in the refrigerator for at least 2 hours or overnight.
Make the Raspberry Sauce:
Combine raspberries, sugar, and vanilla extract in a blender or food processor. Blend until smooth.
Strain the mixture through a fine-mesh sieve to remove seeds (optional). Chill the raspberry puree in the refrigerator.
Combine and Churn:
Once both the ice cream base and raspberry sauce are thoroughly chilled, mix them together until well combined.
Pour the mixture into your ice cream maker and churn according to the manufacturer’s instructions (usually 20-30 minutes).
Freeze:
Transfer the churned ice cream to a freezer-safe container and freeze for 2-4 hours for a firmer texture.