Pour the apple cider or apple juice into the slow cooker.
You can wash and slice the orange, add the cloves to the orange slices, and then add the slices to the slow cooker. Or you can wash and peel the orange and stick the cloves all over in the orange, then add the slices to the slow cooker.
Add the brown sugar, allspice, and cinnamon sticks to the cider in the slow cooker, and give it all a good stir.
Put the lid on the slow cooker, and cook everything on low for about 4 hours.
Strain out the oranges, cloves, and cinnamon sticks.
Serve it in your favorite mugs, and maybe add a cinnamon stick for garnish.