Layout a piece of cheesecloth and fold it back over onto itself to create a double-thick piece. Place the cinnamon sticks and cloves on the cheesecloth. Bring up the corners of the cloth and tie with a string to make a little bag.
Add cider, cranberry juice, brown sugar, cranberries, and spice bag to your crock pot.
Cover and cook on HIGH for 2 hours, until the cider is nice and hot. Use a spoon to fish out the spice bag, then discard it.
Use a ladle to portion the cider into mugs. Be sure to get some cranberries in each glass. For adults, add 2 ounces of rum or vodka before filling your glass, if desired.