Fill a pot with water and season with salt. Bring to a light boil and add the pasta and cook according to packet instructions. Remove 2 minutes before al dente cooking time. Reserve 1 cup of pasta water and keep pasta in a colander on the side for later.
In the same pot you used to cook your pasta, melt the butter on a low to medium heat. Add the shallot and 2 cloves of garlic and saute until softened for 2-3 minutes. Add the heavy cream and cream cheese and stir until combined and creamy. Add 3/4 cup of Parmesan and turn up the heat slightly to allow the sauce to thicken for 2 minutes, then bring back down to a low heat. Add nutmeg, pepper and salt (if needed.) Then add the spinach and mix continuously to wilt the spinach. Stop when the spinach is wilted and still bright green.
Add the pasta to the sauce and mix well, taste and add more seasoning if needed. If the sauce is too thick, add some pasta water, ¼ cup at a time.
In a skillet over medium heat, add olive oil and panko breadcrumbs along with the remaining minced garlic, remaining parmesan, parsley, salt, pepper and red chili flakes. Toast, while tossing constantly, until golden brown.
Plate the pasta and top with the breadcrumbs. Feel free to add extra Parm for topping along with lemon zest and lemon juice. Enjoy immediately!