Add remaining ingredients and blend again until smooth.
To roast the butternut squash, preheat the oven to 425°F. Line a baking sheet with parchment (baking) paper or foil. Cut a medium butternut squash in half lengthwise. Scoop out the seeds from each half. Lightly rub the halves with a little oil. Roast cut side down for 20 minutes, turn squash over and roast for 10-20 minutes longer, or until very tender when pierced with the tip of a knife in the thickest part. Let cool slightly before using for this recipe. Store leftovers, wrapped, in the refrigerator.
Swap in acorn squash, kabocha squash or sweet potato for the butternut squash.
Add 1 date or a bit of maple syrup for a slightly sweeter smoothie.
If you don't want a warm smoothie, keep ingredients at room temp for a room temp beverage, or freeze squash before adding to make a refreshingly cold smoothie.