In a large pot, combine apple cider, apple juice, brown sugar, granulated sugar, and cinnamon sticks.
Bring the mixture to a gentle boil, then reduce the heat and simmer uncovered for 30 minutes. Stir occasionally.
Remove from heat and let cool completely to room temperature (around 1 hour).
Stir in the vanilla extract and apple pie spice (if using).
Pour the cooled liquid into clean mason jars or bottles using a funnel.
Chill in the fridge for at least a few hours before serving for the best flavor.
Serve warm or cold. Can be reheated gently on the stove.