Measure 3/4 cup (50 grams) of the stuffing mix into a quart size zip top bag and seal, pushing any air out. Crush the crumbs with a rolling pin, meat mallet, or even a large can until finely ground. Remove the crumbs to a pie pan or plate and set aside.
Melt the butter in a 10-inch skillet over medium heat. Add the onion, celery, and 1/2 teaspoon of the kosher salt and sauté, stirring frequently, until the vegetables begin to brown, 4-5 minutes. Finish with the sage and thyme leaves and cook 1 more minute. Remove this mixture to a small bowl to cool for 5 minutes.
Place the turkey in a large mixing bowl along with the remaining salt, pecans, the remaining stuffing mix, marjoram, black pepper, nutmeg, parsley, egg, and the cooled vegetable mixture. Thoroughly combine with your fingers. Scoop the meatball mixture with a tablespoon into 24 equal portions (42-43 grams or 1 1/2 ounces each) and place them on the sheet pan. They don't have to be perfect balls at this point. Refrigerate for 30 minutes (or cover and store overnight to finish the next day.)
Heat the oven to 400℉ with a rack in the middle position.
Using scissors or a utility knife, separate the egg carton lids from the side that holds the eggs. Form trays by nesting the egg cup sides into the lids.
When 30 minutes are up, roll each portion into a ball then thoroughly coat each with the crushed stuffing crumbs. Return to the sheet pan then spray the tops of the balls generously with cooking spray. Place lubed side down into the egg cartons, then spray the tops with additional spray.
Place the cartons in the oven and bake for 25 minutes, or until the internal temperature hits 160℉.
Serve the meatballs hot, or at room temperature, dipped into our Tart Cranberry Dipping Sauce, if desired...and it will be, desired that is.