Place old fashioned oats in a bowl and pour 2 cups of water.
Add the cinnamon stick and mix well.
Leave it to soak for 30 minutes or even better, overnight.
Transfer oats, soaking water, and cinnamon stick to a blender and blend until smooth.
Strain the oats mixture into a large pitcher.
Add vanilla extract and brown sugar, then mix well to dissolve the sugar.
Add the remaining 8 cups of water to the pitcher and mix.
Taste and adjust sweetness to your liking.
Serve in glasses with crushed ice and sprinkle a bit of cinnamon powder on top.
Notes
Oats are a superfood packed with fiber, vitamins, and minerals besides being naturally gluten-free, so perfect for people with specific dietary needs.
Replace 2 cups of water with 2 cups of almond or coconut milk for a creamier version.
This oat drink keeps nicely in the fridge for up to 3 days, just make sure to store it in a large container with a tight lid to prevent it from absorbing other smells.