01 -
Preheat oven to 350°F (175°C).
02 -
Bring a large pot of water to a boil and cook the spaghetti noodles 2 minutes less than package directions. The pasta will finish cooking in the oven. Drain and set aside.
03 -
In a large skillet over medium-high heat, brown the ground beef, breaking it into small crumbles. Add the diced onions and cook until beef is fully cooked. Add chopped garlic and cook for 2 minutes more. Season with salt and pepper, then stir in marinara sauce until well combined.
04 -
Add the drained spaghetti to the skillet with the meat sauce, stirring until all noodles are thoroughly coated.
05 -
In a mixing bowl, combine ricotta, ½ cup milk, and Italian seasoning, stirring until smooth.
06 -
Spray a 9×13 inch baking dish with cooking spray. Spread half of the spaghetti mixture evenly in the dish. Top with the ricotta mixture, spreading to cover. Sprinkle with mozzarella cheese, then add the remaining spaghetti mixture as the final layer.
07 -
In a mixing bowl, combine the biscuit mix (setting aside the seasoning packet), shredded cheddar cheese, and 2 cups milk. Stir until most lumps are gone. Pour batter evenly over the layered pasta.
08 -
Place the dish in the oven and bake until the biscuit topping is golden brown, about 50-55 minutes.
09 -
Remove from oven. Mix the reserved biscuit seasoning packet with melted butter and brush over the biscuit topping. Let the casserole rest for 5 minutes to allow the biscuit topping to absorb the butter.
10 -
Slice into portions and serve hot.