In a large mixing bowl, combine the ricotta cheese, half of the mozzarella cheese, diced ham, cooked spinach, cooked pasta, egg, garlic powder, onion powder, black pepper, salt, and red pepper flakes (if using). Stir until well combined.
Grease a 9×13 inch baking dish. Transfer the pasta and ham mixture to the dish, spreading it out evenly.
Top with the remaining mozzarella cheese and grated Parmesan cheese. Evenly distribute the breadcrumbs on top for a crunchy finish.
Place the casserole in the preheated oven and bake for 25-30 minutes, or until the cheese is bubbly and golden brown.
Remove from the oven and let it cool for about 5-10 minutes. Garnish with freshly chopped parsley before serving.
Notes
For an extra creamy texture, consider mixing in a dollop of sour cream or Greek yogurt.
If you desire a little kick, consider adding optional red pepper flakes.
For added crunch, use panko breadcrumbs or crushed crackers.
For an aromatic touch, sprinkle dried herbs such as oregano or parsley on top before baking.
Serve with a fresh green salad, steamed or roasted vegetables, or crusty bread.