Prepare Your Baking Dish:

1. Spray a large baking dish with cooking spray to prevent sticking.

Add Cranberries, Sugar, and Cinnamon:

1. Place 2-12 oz packages of fresh cranberries into the baking dish. Sprinkle with 2 cups of sugar and a teaspoon of cinnamon, ensuring an even coating over the cranberries.

Cover Tightly and Bake:

1. Cover the dish tightly with foil and then secure it with a lid. This double layer prevents splattering as the cranberries cook. Place the dish in a preheated oven at 350°F and bake for 1 hour.

Add Marmalade and Lemon Juice:

1. Once out of the oven, immediately stir in one 12 oz jar of sweet orange marmalade and 3 tablespoons of lemon juice. This combination brings out the natural flavor of the cranberries and balances the tartness with a bit of sweetness.

Cool Completely:

1. Cover the dish and allow the sauce to cool completely. This step can be done a day in advance if you prefer. The sauce will thicken as it cools, giving it that classic, spreadable texture.

Serve and Enjoy:

1. Stir before serving to ensure all ingredients are well combined, then spoon into a beautiful serving dish. This cranberry sauce is the perfect addition to any holiday meal.