Pour 4 cups of cider into a medium saucepan with a piece of cinnamon stick and bring to a boil. Continue to boil for the lid off for about 30 minutes until the liquid has reduced by half. You should end up with 2 cups of liquid at the end.
Remove the reduced cider from the heat, remove the cinnamon stick and stir in the vanilla extract. Set the cider aside to cool for a while.
Pour into ice pop molds and set in the fridge. If your ice pop mold doesn't come with sticks, you can insert popsicle sticks after the first hour of freezing.
The popsicles need to freeze for about 4 to 6 hours before they're ready to unmold and eat.