01 - Preheat oven to 375°F. Line a baking sheet with parchment paper or lightly grease a 9x5 inch loaf pan.
02 - In a large mixing bowl, add ground beef, eggs, Parmesan cheese, milk, garlic, onion, parsley, breadcrumbs, salt, pepper, Italian herbs, and red pepper flakes. Mix gently with hands or a spatula until just combined—avoid overmixing to keep the texture tender.
03 - Transfer the mixture to the prepared baking sheet and form into an 8x4 inch loaf, or press firmly into the loaf pan, smoothing the top evenly.
04 - Spread tomato sauce or ketchup over the top surface, then sprinkle evenly with the remaining 1/3 cup Parmesan cheese.
05 - Bake for 50 to 55 minutes until a meat thermometer inserted into the center reads 160°F.
06 - Let meatloaf rest for 10 minutes before slicing to retain juices. Garnish with additional fresh parsley and serve warm.