Preheat oven to 400 degrees F.
Line a baking sheet with parchment paper or silicone liners.
Place the squash cut side down on the prepared baking sheet.
Roast for 30 minutes or until tender.
Set aside for 10 minutes or until cool enough to handle. Scoop out the flesh and discard the skins.
Transfer squash to a blender along with the remaining ingredients. Puree until completely smooth.
Season to taste with salt and pepper. Serve immediately.
Refrigerate any leftovers in an airtight container for up to five days.