Add the cranberries, orange juice, maple syrup, and cinnamon to a saucepan with matching lid over medium-high heat. Bring to a boil, then reduce heat to medium-low, cover, and cook for 10 minutes, until the cranberries have popped and the sauce has thickened and reduced. If the sauce is still thin, continue to cook for an additional 5 minutes, until desired consistency is achieved.
For the graham cracker crust, place the two boxes-worth of graham crackers into a food processor and pulverize until you have fine crumbs. Adding 4 tablespoons-worth of softened butter pieces at a time, pulse the food processor with the butter. Continue for the rest of the butter, until the graham cracker crust comes together in a flaky, slightly-crumbly dough.
Pat the graham cracker crust into the bottom of a 9×13 inch pan and slightly up the sides to create a 1/4 inch thick crust.
For the cheesecake filling, add the condensed milk, cream cheese, lemon juice, and vanilla extract to a large bowl, then beat with an electric mixer or stand mixer for 2-3 minutes, until mixture is smooth and fluffy.
Pour the cheesecake filling on top of the crust, smoothing to even it out, then pour the cranberry sauce over top.
Refrigerate for at least 4 hours, then slice and serve!