1 Preheat The Oven To 350F. Cut The Butternut Squash Lengthwise In Half* And Scoop Out The Guts And Seeds And Discard Them (Or Save The Seeds And Toast Them). Pour 1/4 Cup Of Water Into A Pyrex Or Ceramic Baking Dish And Place The Butternut Squash Halves Cut Side Down. Bake For 40 Minutes Or Until A Fork Easily Pierces The Squash. Allow To Cool For 10 Minutes. Scoop Out The Squash Flesh From The Skins And Put Into A Blender. Discard The Skins. 2 Saute The Onion In The Olive Oil Over Medium-High Heat In A Small Skillet Until Just Beginning To Brown, About 3-4 Minutes. Add The Onions To The Blender. Add 1 Cup Water, The Parmesan, 2 Teaspoons Salt And Nutmeg And Puree. If You Need A Little More Water, Add It. Pour The Sauce Into A Small Pot Set Over Low Heat. Mix In The Sour Cream And Warm It Through. Do Not Let The Sauce Boil. 3 Fill A Pot With Water And Salt (1 Tablespoon Of Salt For Every 2 Quarts Of Water). Set Over High Heat To Bring To A Hard Boil. Add The Pasta And Cook At A Hard Boil, Uncovered Until Al Dente. When The Pasta Is Ready, Drain And Put It Into A Bowl. Mix With A Little Of The Sauce And Serve. Add A Dollop Of Additional Sauce And Some Parsley Right When You Bring It To The Table.