01 - Bring a large pot of salted water to a boil. Cook pasta according to package directions until al dente. Reserve ½ cup of pasta cooking water, then drain and set aside.
02 - Heat olive oil in a large skillet over medium-high heat. Add ground beef and cook, breaking apart with a spoon, until browned and cooked through, approximately 5–6 minutes. Drain excess fat if needed.
03 - Add diced onion to the skillet and sauté for 2–3 minutes until translucent. Stir in minced garlic and cook for 30 seconds until fragrant.
04 - Mix in chopped sun-dried tomatoes and cook for 1 minute to incorporate flavors.
05 - Pour in beef or chicken broth and bring to a simmer. Let liquid reduce by half, about 3 minutes.
06 - Reduce heat to medium-low. Add heavy cream, parmesan cheese, Italian herbs, and red pepper flakes. Stir until cheese melts and sauce becomes creamy, approximately 2–3 minutes.
07 - Add cooked pasta and baby spinach (if using) to the skillet. Toss to coat thoroughly, adding reserved pasta water as needed for desired consistency. Season with salt and pepper to taste. Serve hot with additional parmesan and fresh basil if desired.