01 -
In a large mixing bowl, combine ground beef, breadcrumbs, grated Parmesan cheese, egg, minced garlic, Italian seasoning, salt, and black pepper until homogenous.
02 -
Form the mixture into 1-inch to 2-inch meatballs. Heat olive oil in a large skillet over medium heat and sear the meatballs on all sides until browned, about 8 minutes. Do not cook through; they will finish baking in the oven.
03 -
Bring a large pot of salted water to a boil. Cook spaghetti 1–2 minutes less than package directions for al dente texture. Drain and toss immediately with 1 tablespoon olive oil to prevent sticking.
04 -
Preheat oven to 375°F.
05 -
Spread 1 cup of marinara sauce on the bottom of a 9×13-inch baking dish. Layer half the cooked spaghetti evenly over the sauce. Arrange seared meatballs over the spaghetti. Pour the remaining marinara sauce over the meatballs and spaghetti. Sprinkle with garlic powder and Italian seasoning, then top evenly with shredded mozzarella and grated Parmesan cheese.
06 -
Cover the baking dish with foil and bake for 15 minutes. Uncover and bake an additional 10–15 minutes or until the cheese is melted and golden brown.
07 -
Allow the casserole to rest for 5 minutes before garnishing with fresh basil or parsley if desired. Serve warm.