Saute onions, cranberries, brown sugar and cider vinegar in a skillet over medium heat, until onions are translucent. Combine onion mixture, powdered pectin, orange peel and apple juice in a large pot. Bring to a boil over medium-high heat. Add sugar, stirring until dissolved. Return to a rolling boil. Boil hard one minute, stirring constantly. Remove from heat. Skim foam if necessary. Ladle hot marmalade into hot jars, leaving 1/4-inch headspace. Adjust two-piece caps. BWB 15 minutes.