In a glass jar or airtight container, combine the rolled oats, protein powder, chia seeds, cinnamon, ginger, and nutmeg.
Whisk or stir the dry ingredients until the protein powder is evenly distributed and no clumps remain.
Add the almond milk, Greek yogurt, and maple syrup; stir vigorously until well combined.
Fold in the finely grated carrots, walnuts, and raisins.
Seal the container with a lid and refrigerate for at least 4 hours, ideally overnight for 8 hours.
Before serving, stir the mixture and add a splash of additional almond milk if a thinner consistency is desired.