Whisk together all the ingredients in a bowl. Cover and refrigerate for at least 2 hours to thicken (or overnight).
To serve, layer with toppings of your choice and a drizzle of maple syrup if desired.
Notes
If using non-dairy milk, almond milk is the best as it has a thicker consistency. If you choose to use rice or coconut milk, you may need to add a bit more chia seeds to thicken the mixture.