In a jar or bowl, whisk together the milk, agave, vanilla, cinnamon, and (if using) salt
Stir in the chia seeds.
Let it sit for 5–10 minutes, then stir again to break up any clumps.
Cover and refrigerate for at least 2 hours, or overnight.
Stir before serving — add toppings like fruit, nuts, or granola if you like!