Put the eggs, 1 cup milk and sugar into a blender. Blend until the sugar is dissolved and smooth.
Whisk the egg mixture into the chocolate mixture and stir until smooth. Cook for 2 minutes over low heat. Remove from heat and add heavy cream, remaining milk, chocolate extract and vanilla.
Chill thoroughly. Transfer to your ice cream maker and freeze according to manufacturer's directions.
Makes slightly more than 1 quart.
Recipe modified from That My Home Ice Cream Recipes
Recipe by Recipes Food and Cooking at https://recipesfoodandcooking.com/2007/02/24/homemade-chocolate-ice-cream/