In a large mixing bowl, combine the rolled oats, almond milk, Greek yogurt, peanut butter, honey or maple syrup, vanilla extract, cinnamon, and salt. Stir well until all ingredients are fully combined.
Divide the mixture evenly into two or four jars or containers with lids.
Seal the jars and refrigerate them overnight (or for at least 4 hours) to allow the oats to soak and soften.
In the morning, give the oats a good stir. If the mixture is too thick, add a splash of milk to reach your desired consistency.
Top with your choice of sliced bananas, chopped nuts, chocolate chips, or berries before serving.