Preheat your oven to 425℉ degrees and line a baking sheet with parchment paper or a silicone baking mat.
Use a sharp knife to cut the butternut squash in half lengthwise, then use a spoon to scrape out the seeds and stringy membrane; save to roast separately or compost. Place them with the cut sides down on the baking sheet. Roast for 45 - 50 minutes, or until fork-tender. Let stand until cool enough to handle.
Meanwhile, in a large saucepan over medium heat, add the onion, carrots, celery, pear, ginger, garlic, and a splash of the vegetable broth; just enough to prevent the vegetables from sticking. Sauté, stirring periodically, until the vegetables are tender, aromatic, and lightly browned, about 8 - 10 minutes.
Scoop the roasted butternut squash out of the skin and directly into the pot, discarding or composting the skin. Add the miso, crushed red pepper flakes, remaining vegetable broth, and non-dairy milk, mixing gently to combine. Simmer for 10 minutes for the flavors to meld.
Carefully transfer the mixture to a blender in batches, or use an immersion blender in the pot, and blend until smooth, or leave part of the soup unblended for more texture. Pour into bowls and top with a drizzle of non-dairy milk and additional pinch of crushed red pepper flakes, if desired, followed by fresh cilantro. Enjoy hot.