Cook the pasta according to the package instructions in a large pot of boiling salted water. Drain well and set aside.

In a large skillet, heat the olive oil over medium-high heat. Add the ground beef and cook until browned, about 3-5 minutes, breaking it apart as it cooks. Drain the excess fat and set beef aside.

In the same skillet, add the diced onion and cook for 2 minutes while stirring frequently. Add the minced garlic and cook until fragrant, about 1 minute.

Whisk in the flour until it is lightly browned, which takes about 1 minute.

Gradually whisk in the beef stock and stir to combine. Add the marinara sauce and mix in the Italian seasoning, dried parsley, dried oregano, and smoked paprika.

Bring the mixture to a boil, then reduce the heat and let it simmer, stirring occasionally, until it reduces and thickens slightly, about 6-8 minutes.

Stir in the cooked pasta and return the beef to the skillet.

Pour in the heavy cream and heat through for about 1-2 minutes. Taste and adjust with salt and pepper as desired.

Finally, stir in the sour cream and fold in the cheddar cheese until it melts, which should take another 1-2 minutes.

Serve immediately, garnished with parsley if desired.