Preheat oven to 350 F. Spray muffin pan with nonstick cooking spray or line muffin tin with 12 silicone muffin liners.
Combine oats and milk in a small bowl. Mix well. Let stand for 3 minutes or until oats are softened.
To a large mixing bowl, add ground chicken, the oat mixture, hot sauce, carrot, garlic, onion, egg, parmesan cheese (if using), salt and pepper. Mix ingredients until combined.
Divide chicken mixture into muffin cups, filling 3/4 of the way full.
Bake for 20 minutes. Remove from oven and top each meatloaf muffin with marinara sauce. You can also add some grated cheese at this time if you wish. Place back in the oven for an additional 5-10 minutes or until the meatloaf reaches an internal temperature of 165 F.
Allow to cool for several minutes before removing from the muffin tin. Garnish with finely chopped fresh parsley if desired. Serve warm.