To make your own butternut squash puree, simply cut the top off a butternut squash, slice it lengthwise (I enlist my hubby for this task), drizzle with about a tsp of olive oil, sprinkle with salt and pepper, and roast on a large baking sheet, cut side down, for 45-50 minutes at 400 degrees, until fork tender. Let cool enough to handle, then scoop out seeds and discard. Scoop out remaining squash and discard skins. Puree squash in blender or food processor until very smooth, baby food consistency. Any extra squash puree can be refrigerated for up to a week or frozen for longer storage.