Heat olive oil in a large oven-safe skillet over medium heat.
Add diced onion and cook for 3-4 minutes until softened.
Add ground beef and cook, breaking it apart with a spoon, until browned and cooked through, about 6-8 minutes.
Stir in minced garlic and cook for 1 minute until fragrant.
Pour in marinara sauce and water, then add uncooked penne pasta. Stir to combine.
Season with dried Italian seasoning, salt, and black pepper.
Bring the mixture to a simmer, cover the skillet, and cook for 15 minutes, stirring occasionally, until pasta is tender.
Remove the skillet from heat and dollop cottage cheese evenly over the pasta mixture.
Sprinkle shredded mozzarella and grated Parmesan cheese on top.
Place the skillet under a preheated broiler for 3-5 minutes until the cheese is melted and bubbly. Watch carefully to prevent burning.
Remove from oven and garnish with chopped fresh basil before serving.