Bring ¼ cup of water to a boil. Steep tea bags in the water for 5 minutes.
Remove and discard the bags and stir in the sugar until the sugar dissolves. Stir cold coffee into the chai mixture.
Fill a 16-ounce cup with (about) 1½ cups of ice. Pour chai/coffee mixture over the ice. Add milk, and stir to combine.
Add whipped cream and cinnamon if desired, and enjoy!
Notes
*If you prefer a particularly sweet drink, use 1 tablespoon of sugar.*To substitute espresso for coffee, use 1 shot of (cooled) espresso and increase the milk as needed to fill a 16-ounce cup (about ¾ cup milk total)