Add all ingredients to a large crockpot and cover with water. Cook on high for 6 hours or low for 10 hours. When the apples and oranges are very soft, mash with a potato masher or slotted spoon, making sure the ingredients break down and the fruit releases its juice. Cook for an additional hour, stirring occasionally and mashing fruit against the sides and bottom of the crockpot. Once the cooking time is complete, use a fine-mesh strainer to separate the chunks from the juice, collecting the juice in a large bowl. Add the cinnamon sticks back to the strained juice and cool until room temperature or cover with plastic wrap and refrigerate overnight. Strain cider one more time to remove the cinnamon sticks and any other solids. Serve warm with cinnamon sticks or cold. Store in the refrigerator for up to 7 days.