You can get dried tart cherries at the grocery store next to the raisins and other dried fruit. I like to get the big bag at Costco. This recipe is from Eric's sister Reesy, who adapted it from Cook's Illustrated. Also featured on Epicurious.
Dark Chocolate Cherry Oatmeal Cookies - https://thefoodcharlatan.com/chocolate-cherry-oatmeal-cookies-recipe/