Combine the milk and vanilla Greek yogurt in a mason jar or bowl, whisking until smooth.

Add oats, chia seeds, protein powder (if using), cinnamon, nutmeg, ginger, and salt into the wet mixture. Stir until fully combined.

Fold in the shredded carrots and chopped walnuts gently, ensuring an even distribution.

Let the mixture sit at room temperature for about 10 minutes to thicken.

Cover and refrigerate for at least 3 hours or overnight.

Before serving, stir well, and top with additional Greek yogurt and walnuts, if desired.