Mix all the spices together and store them in an airtight container for up to 3 months.
In a medium saucepan, bring water, milk, 2 teaspoons of the Chai seasoning, and tea bags to a boil over medium-high heat, whisking every 30 seconds or so to prevent the milk from scalding.
Once boiling, reduce the heat to medium-low, and let simmer for 2-3 minutes, to let the tea bags continue to steep.
Discard the tea bags and stir in oats. Cook until thick, about 5 minutes, stirring often.
Remove the oatmeal from the heat and stir in the vanilla extract. Serve immediately or cool and store in the refrigerator.
