In a large bowl, mash together all of the ingredients, except the maple syrup, until the bananas are as smooth as possible.
Taste and add maple syrup, 1 teaspoon at a time, until you get your desired level of sweetness.
Transfer the mixture to a pint jar, and stick it in the fridge. Go to sleep. Wake up, and eat your oats!
If you want your oats warm, my preferred method is the microwave. Just stick the jar (without the lid!) in the microwave for 45-90 seconds, until it's warm. You can warm these on the stovetop, but I feel like that defeats the purpose of overnight oats a little bit. You do you, though!Nutritional information is for the oats with no maple syrup, since it's optional.