1. Bring a large pot of salted water to a boil. Cook linguine according to package instructions until al dente. Reserve ½ cup pasta water, then drain and set pasta aside.

2. In a deep skillet, heat olive oil over medium heat. Add chopped onion and sauté until translucent, about 3–4 minutes. Add minced garlic and cook for 30 seconds.

3. Add ground beef to the skillet. Break apart with a wooden spoon and cook until browned. Season with salt, pepper, and Italian seasoning. Drain excess fat.

4. Stir in marinara sauce. Reduce heat and let it simmer for 10–15 minutes, stirring occasionally.

5. In a separate saucepan over low heat, melt cubed Velveeta with milk. Stir constantly until smooth. Add garlic powder, black pepper, and red pepper flakes (if using).

6. Return cooked linguine to the pot or a large bowl. Pour cheese sauce over pasta and toss gently to coat. Add reserved pasta water as needed to loosen sauce.

7. Transfer creamy pasta to plates or a serving dish. Spoon hot beef marinara over top and sprinkle with shredded mozzarella.

8. Optional: Place under broiler for 2–3 minutes until cheese is bubbly and golden.

9. Garnish with parsley or oregano and serve immediately.