Add the cinnamon sticks (break them if you need), whole cloves, and whole allspice on a cheesecloth you've folded in half. Bring up corners of cheesecloth and tie them together with a string to form a small spice bag.
Pour the cider and dump the brown sugar in the crockpot and stir until sugar dissolves. Add the spice bag and the peeled + slice orange on top (the peel sometimes makes it bitter).
Cover and cook on low for 2-3 hours or until heated through. Discard spice bag and serve!