Turn the Girl Scouts' best-selling cookie into a refreshing frozen treat with this recipe. For an extra dose of minty goodness, use any extra cookies to build mini ice cream sandwiches.
Combine cream, milk, mint, and salt in a medium saucepan. Bring to a simmer. Immediately remove from heat and let steep at least 1 hour and up to overnight, covered, in the refrigerator.
In a medium bowl, whisk together sugar and yolks; set aside. Remove mint from cream mixture; discard mint. Bring milk mixture just to a simmer. Using a measuring cup or ladle, slowly pour about 1/2 cup hot milk mixture into the egg-yolk mixture, whisking constantly. Continue adding milk mixture, about 1/2 cup at a time, until it has all been added.
Pour mixture back into saucepan and cook over low heat, stirring constantly with a wooden spoon, until mixture is thick enough to coat the back of a wooden spoon, 3 to 5 minutes. The custard should retain a line drawn across the back of the spoon with your finger. Pour through a fine sieve into a medium bowl. Stir occasionally until cooled. Cover and transfer to refrigerator until chilled, at least 1 hour and up to overnight.
Pour custard into a 2-quart ice cream maker; add chopped thin mints and process according to manufacturers' instructions until set but not hard.
Transfer the soft ice cream to a loaf pan, cover and freeze at least 4 hours and up to overnight.