Preheat your oven to 400°F (200°C) and prepare a baking sheet lined with parchment paper.

Spread diced butternut squash on the baking sheet, drizzle with olive oil, season with salt and pepper, and roast for 25-30 minutes.

While the squash roasts, bring a large pot of salted water to a boil, add pasta, and cook according to package instructions. Reserve 1 cup of pasta water before draining.

Heat remaining olive oil in a large skillet, add onion and sauté for about 5 minutes. Stir in garlic, sage, and red pepper flakes, cooking until garlic is golden.

Add roasted squash to the skillet, pour in vegetable broth, mash some squash, and stir in cream or coconut milk.

Toss cooked pasta with the sauce, using reserved pasta water to achieve desired consistency, and adjust seasoning to taste.

Serve in bowls, garnishing with toasted walnuts, grated Parmesan, and fresh sage leaves.