Bring a large pot of salted water to a boil and cook the fettuccine until it reaches al dente texture, then drain while keeping 1 cup of the pasta water.
Heat a skillet over medium heat and cook the ground beef, breaking it up as it browns; season with salt and pepper and cook through.
Shift the beef to one side of the pan and add the minced garlic, sautéing for about a minute until it releases its aroma.
Pour in the heavy cream and slowly stir in the Parmesan cheese, continuing to mix until the sauce becomes smooth and creamy.
Add the fresh spinach to the skillet, allowing it to wilt and incorporate into the sauce while scraping any browned bits from the bottom.
Mix the cooked pasta into the creamy beef sauce, adding reserved pasta water gradually until the desired sauce consistency is achieved; serve immediately while warm.
