Make the base: In a medium saucepan over medium-low heat, barely simmer the heavy cream, milk, granulated sugar, and salt. Stir often. Once you see bubbles along the perimeter, remove pot from heat. You don't want it to boil but the mixture should be warm.
In a medium bowl whisk the egg yolks. While whisking, slowly pour 1 cup of the hot cream into the egg yolks. Now, whisk the egg yolk mixture into the pot with the remaining hot cream.
Place the pot over medium-low heat and cook until it reaches 165°F on an instant read thermometer, the mixture should coat the back of a spoon.
Strain the mixture through a fine mesh strainer. Cover and place in the refrigerator to cool.
Make the Raspberry Puree
Make the puree: in a blender puree the raspberries, sugar, and vanilla extract. Add more sugar as you see fit. But remember, you'll be adding the fruit puree to the ice cream base (that's sweet). Optional: if you want to remove the raspberry seeds (I did), pour the mixture through a fine mesh strainer.
Stir the puree into the ice cream base. Cover and chill in the refrigerator for 4 hours or until completely chilled.
Remove the raspberry ice cream mixture from the fridge. Churn in an ice cream machine according to manufactures instructions.
For soft serve raspberry ice cream serve immediately, or transfer mixture to a large freezer safe container. Optional: fold in a handful of fresh raspberries. Freeze for 2 hours or until hard. When ready to serve, remove ice cream from the freezer and scoop into individual bowls. Enjoy!
Lot's of step-by-step photos and FAQ in the blog post if you need them!