Bring a large pot of salted water to a boil. Cook fettuccine according to package directions until al dente. Reserve 1 cup of pasta water, then drain the pasta.

While the pasta cooks, heat olive oil in a large skillet over medium heat. Add minced garlic and sauté for 30-60 seconds until fragrant, being careful not to let it brown.

Stir in the sliced sun-dried tomatoes and red pepper flakes. Pour in the heavy cream, bring to a gentle simmer, and let it cook for 2-3 minutes until slightly thickened.

Reduce heat to low. Gradually whisk in the grated Parmesan until melted and smooth. Add baby spinach and stir constantly for about 1 minute until just wilted. Season with salt and black pepper to taste.

Add the drained pasta to the skillet. Toss thoroughly with tongs, adding reserved pasta water a tablespoon at a time if needed to loosen the sauce until it clings beautifully to every strand.