Add the milk to a small saucepan over medium heat. Whisk in the chia seeds, maple syrup, vanilla extract, and ground cinnamon (if using).
Bring to a low simmer and whisk continuously to prevent sticking to the bottom. Heat the mixture until it starts to thicken, about 3-5 minutes.
Once warmed, remove the saucepan from heat. The chia pudding should have a thick, pudding-like consistency. Spoon the warm chia pudding into serving bowls.
