In a medium saucepan set over medium-low heat, whisk together the milk, cream & half of the graulated sugar, salt & vanilla. Bring the mixture just to a boil.
While the milk mixture is heating, combine the yolks & remaining sugar in a medium bowl. Using a hand mixer on low speed or a whisk, beat until the mixture is pale and thick.
Once the milk/cream mixture has come to a slight boil, whisk about 1/3 of the hot mixture into the egg yolk/sugar mixture to temper the eggs, careful not to scramble the raw yolks. Once combined, add another 1/3 of the milk/cream mixture, then returned that combined mixture back to the saucepan.
Stir the mixture constantly over low heat until it thickens slightly and coats the back of the spoon. This mixture must NOT boil or the yolks will overcook - this process should only take a few minutes.
Pour this mixture through a fine mesh strainer. Bring the ice cream base to room temperature. Cover & refrigerate 1 to 2 hours, or overnight, until fully chilled.
Once mixture is fully chilled, remove from refrigerator & add in mint extract (to taste). Stir to mix fully and incorporate mint flavor. OPTIONAL: add food coloring to ice cream base to desired shade.
Add ice cream base to ice cream maker and follow instructions based on the model you own. For Cuisinart Ice Cream Maker, turn ice cream maker on, pour the mixture into the frozen freezer bowl and let mix until thickened, about 20 minutes.
When the ice cream mixture is almost fully churned, gradually add the crushed cookies through the top of the ice cream maker; let mix until fully combined.
The ice cream will have a soft, creamy texture. If a firmer texture is desired, transfer the ice cream to an airtight container and place in the freezer for at least another 2 hours, or longer.