You could even
substitute roasted butternut squash and walnuts for a different version.
You can even
substitute roasted butternut squash puree.
Not exact matches
I also think that most any
roasted winter
squash —
butternut, kabocha, acorn — will
substitute just fine.
Another option if you're in a hurry is
substituting two cups of canned pumpkin for the
roasted butternut squash.