How to Make It
Peel, core, and remove seeds from apples. Reserve flesh for another use.
Bring peels, cores, and 6 cups water to a boil in a Dutch oven over high. Reduce heat to medium-low; simmer 45 minutes. Pour mixture through a fine mesh strainer into a large saucepan, discard solids.
Whisk in sugar and pectin. Add cinnamon sticks, and bring to a boil over high. Boil 2 minutes. Remove from heat; discard cinnamon sticks. Pour into sterilized jars, filling to 1/4-inch from top, and cool completely, about 30 minutes. Cover with lid, and chill 12 hours before serving.