Heat the oil and butter together in a large saucepan over medium-high heat and saute the onion till translucent.
Add squash, broth, thyme and cayenne pepper. Bring to a boil, then reduce heat and simmer, covered, for 20 minutes, or until squash is tender.
In a blender, puree squash mixture with the cream cheese (in batches) until smooth; return to the saucepan and heat through, BUT DON’T BOIL!
Salt and pepper to taste and serve.