In a mixing bowl, combine rolled oats, almond milk, vanilla protein powder, diced apple, ground cinnamon, chia seeds, maple syrup, Greek yogurt, and salt.
Stir the mixture well until all ingredients are fully combined.
Divide the mixture evenly into two jars or containers with lids.
Seal the jars and refrigerate overnight or for at least 4-5 hours.
In the morning, give the oats a good stir. If desired, add a little more almond milk to reach your preferred consistency.
Top with chopped walnuts or almonds before serving.
Notes
You can customize the toppings based on your preference.