Combine apple cider and maple syrup in a saucepan and bring to a boil over medium-high heat. Continue cooking until reduced to 1/2 cup, then remove the pan from the heat. Stir in 1 tablespoon thyme, 1 tablespoon marjoram, and lemon zest. Stir in butter until melted and season with salt and pepper. Cover and refrigerate until cold.

Preheat the oven to 375 degrees F (190 degrees C). Place the rack in the lower third of the oven.

Place turkey on a rack set in a roasting pan. Reserve 1/4 cup maple butter for gravy and rub remaining maple butter under the skin of the breast and over the outside of turkey. Arrange onion, celery, carrots, turkey neck, and giblets around the turkey. Sprinkle 1 tablespoon thyme and 1 tablespoon marjoram over vegetables. Pour 2 cups broth into the pan.

Roast turkey in the preheated oven for 30 minutes. Reduce oven temperature to 350 degrees F (175 degrees C). Cover entire turkey loosely with foil. Continue roasting until a meat thermometer inserted into thickest part of thigh registers 180 degrees F (85 degrees C), about 2 1/2 hours. Transfer turkey to a platter and let stand for 30 minutes.

Strain pan juices into a large measuring cup, remove any excess fat. Add enough chicken broth to pan juices to measure 3 cups. Transfer liquid to a saucepan and bring to a boil.

Mix remaining 1/4 cup maple butter and flour in a small bowl until smooth. Whisk flour and butter mixture into broth mixture. Stir in remaining thyme and bay leaf. Boil until reduced to sauce consistency, stirring occasionally, about 10 minutes. Mix in apple brandy. Season with salt and pepper to taste.