Preheat your oven to 400°F (200°C) and grease a 9x13 inch baking dish.

Finely dice one onion and mince a couple of garlic cloves. Shred about 2 cups of cheddar cheese.

In a large pot, boil salted water and cook the penne pasta for 7-8 minutes until al dente. Drain and set aside.

In a large skillet, heat olive oil over medium heat, add onion, and cook until softened. Then add ground beef and cook until browned.

Add minced garlic and sauté for 30 seconds. Pour in marinara sauce, season with salt and pepper, and simmer for 1-2 minutes.

Combine drained pasta with the beef mixture in the baking dish and fold together gently.

Top with shredded cheddar cheese and bake for about 10 minutes until bubbly and golden.

Let cool for 2-3 minutes before serving.