This recipe originally called for lemon in place of the orange but orange and chocolate translates to Christmas for me. Found the original in The Washington Post who attributed the Ghirardelli Chocolate Cookbook. In homage, consider using Ghirardelli chocolate for this recipe. Whatever chocolate you use, use block chocolate, not morsels. ****dough needs 30 to 60 minute minimum chill in the fridge (good for making the day before)**** These turned out to be the star on the Christmas platters. Several folks would not believe these were not purchased! They are that good with bittersweet chocolate & about 3+ teaspoons orange zest. Will make next with tangerine zest!