1. Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Reserve 1 cup of pasta water and then drain the pasta.
2. In a large skillet, heat the olive oil over medium heat. Add the garlic and sauté for about 30 seconds until fragrant.
3. Add the salmon pieces to the skillet. Cook for about 3-4 minutes, turning occasionally until the salmon is just cooked through. Remove the salmon from the skillet and set aside.
4. In the same skillet, pour in the heavy cream. Stir in the Parmesan cheese and let it melt into the cream, creating a rich sauce. If the sauce is too thick, add a bit of the reserved pasta water to reach your desired consistency.
5. Reduce the heat to low and add the spinach to the creamy sauce. Stir until the spinach is wilted.
6. Return the cooked salmon to the skillet, gently mixing it into the sauce.
7. Add the cooked pasta to the skillet, tossing everything together so the pasta is well coated with the creamy sauce.
8. Season with salt, pepper, lemon juice, and red pepper flakes if using. Stir well to combine all the flavors.
9. Serve immediately, garnished with extra Parmesan if desired.

Remember, cooking is about feeling your way through a recipe. My dad always said, “Taste as you go, and trust your instincts.” So adjust the seasoning to your liking!