Add the unfiltered apple cider, spiced rum, and pure maple syrup into a pitcher and whisk until the syrup is fully incorporated.

Pour the mixture into the main vessel of your Ninja Slushi drink maker.

Turn on the machine and select the "Spiked Slush" preset setting.

Allow the machine to churn for 15 to 20 minutes until the mixture reaches a thick, frozen consistency.

Dispense into glasses, garnish with cinnamon sticks or fresh apple slices, and serve immediately.