Baked Spaghetti and Meatballs Casserole Recipe

Ingredients:
For the Meatballs:
1 pound ground beef
1/2 cup breadcrumbs
1/4 cup grated Parmesan cheese
1/4 cup milk
1/4 cup finely chopped onion
1 egg
1 teaspoon salt
1/2 teaspoon black pepper
1/2 teaspoon garlic powder
1/2 teaspoon dried oregano
1/2 teaspoon dried basil
For the Casserole:
12 ounces spaghetti
1 jar (24 ounces) marinara sauce
1 1/2 cups shredded mozzarella cheese
1/4 cup grated Parmesan cheese
Fresh basil leaves, for garnish (optional)