In a bowl or jar, combine the chia seeds, milk, maple syrup (if using), and vanilla extract.
Stir well to combine and ensure there are no clumps of chia seeds.
Cover and refrigerate for at least 4 hours, or preferably overnight, until thickened.
Stir the pudding before serving. Top with fresh fruit, nuts, or granola as desired.
Notes
You can adjust the amount of sweetener to your preference. This recipe is very versatile; feel free to experiment with different types of milk and add-ins like cocoa powder or cinnamon.