In a mason jar or small bowl add almond milk, chia seeds, peanut butter, and maple syrup (or any other sweetener) and stir with a spoon to combine. The peanut butter doesn't need to be completely mixed with the milk as it is nice to get swirls of peanut butter.
Add oats and stir.
Cover securely with a lid or plastic wrap and set in the refrigerator overnight.
The next day, <g class="gr_ gr_99 gr-alert gr_gramm Grammar multiReplace" id="99" data-gr-id="99">enjoy</g> as is, or garnish with toppings.
Overnight oats will keep in the refrigerator for up to 2 days.