Remove stem & bottom bulge of squash. Peel and cut the rest of the squash into ¼"/.5cm triangles. Spread squash onto parchment lined half sheet tray. Toss with olive oil, salt, and pepper. Roast for 10 minutes at 450°F/232°C. You should have enough squash to nearly fill a half sheet tray.
Toast pine nuts on a small sheet tray in the oven (450°F/232°C), 5-6 minutes.
Bring a large pot of water to a boil. Add salt and pasta. Cook to al dente. Reserve 250ml/1 cup pasta water. Drain & set aside pasta while you build the sauce.
Return empty pasta pot to medium heat. Add 50g butter and sliced sage. Fry sage for 90 seconds until butter has browned. Add reserved pasta water and drained pasta. Reduce heat to low. Stir and toss the pasta while shaking the pan to emulsify the sauce. After about a minute the texture should be silky.
Off heat, add half the toasted nuts, all of the roasted squash, and 50g of parmesan. Stir to gently melt the cheese. Plate up and top with a squeeze of lemon juice, a pinch of parm, chili flakes, pine nuts, and a drizzle of olive oil.