1. Combine Dry Ingredients: In a medium-sized jar (a 16-ounce mason jar works perfectly) or a small bowl, add the old-fashioned rolled oats, protein powder, chia seeds, ground cinnamon, and optional ground nutmeg. Use a spoon to stir these dry ingredients together thoroughly, ensuring the protein powder is well distributed and there are no clumps.

2. Add Wet Ingredients: Pour in the unsweetened almond milk, unsweetened applesauce, and the finely diced apple pieces. If you’re using maple syrup or honey for added sweetness, add it now.

3. Mix Everything Well: Stir all the ingredients together vigorously. Make sure to scrape the bottom and sides of the jar or bowl to ensure all the oats and chia seeds are fully submerged in the liquid and everything is evenly combined. You want to see a consistent mixture, not dry pockets of oats or powder.

4. Seal and Refrigerate: Once mixed, place a lid tightly on your jar or cover your bowl with plastic wrap. Transfer it to the refrigerator.

5. Allow to Soak: Let the oats chill in the refrigerator for at least 4 hours, but ideally overnight (8 hours or more). This soaking time is crucial for the oats to soften, the chia seeds to swell and thicken the mixture, and all the flavors to meld together.

6. Serve and Enjoy: The next morning, remove your overnight oats from the refrigerator. Give them a quick stir. If the mixture is too thick, you can add a splash more milk to reach your desired consistency. Top with additional diced apple, a sprinkle of cinnamon, or a drizzle of maple syrup if desired, then enjoy!