Preheat the oven to 350 degrees
Peel, deseed, and cut a butternut squash into ½” cubes. Add the squash onto a cookie sheet and drizzle with olive oil and ½ teaspoon salt. Bake squash 350 for 30 minutes until soft
After the squash is cooked, add the squash, garlic, heavy cream, parmesan, gruyere, 1 teaspoon salt, cayenne, nutmeg, pepper, butter, and chicken stock into the blender. Blend to combine until creamy. Set aside
Cook the pasta according to package instructions until al dente. Right before the pasta is done, remove 1 cup pasta water and to the blender and blend.
Strain the pasta and add it back into the pot with the butternut squash sauce
Heat the mixture on medium high heat, stirring constantly for 3-5 minutes until the sauce has thickened but is still loose (it will thicken while it sits)