Preheat your oven to 200°C (400°F). Spread the pumpkin chunks on a baking sheet and roast for about 40 minutes until they're tender and caramelized, filling your kitchen with a sweet, toasty aroma.
Once roasted, transfer the pumpkin to a blender or food processor and puree until completely smooth, creating a silky orange mixture.
Meanwhile, cook your pasta in a large pot of salted boiling water until just al dente, about 8-10 minutes. Drain and set aside.
In a large saute pan, melt the butter over medium heat and add the minced garlic. Cook for about 1 minute until fragrant, with a gentle sizzle and a noticeable aroma filling the air.
Pour in the heavy cream and stir in the pumpkin puree, whisking together until the sauce is smooth, creamy, and heated through, about 3-5 minutes. You should see a gentle simmer and a luscious, thick consistency.
Season the sauce with salt, pepper, and a pinch of freshly grated nutmeg, tasting and adjusting the seasoning until perfectly balanced and warming.
Add the cooked pasta into the sauce, tossing gently with a wooden spoon until each strand is coated with the creamy pumpkin mixture, and the dish looks invitingly rich and vibrant.
Finish by stirring in the chopped sage leaves, allowing their fragrant aroma to infuse into the dish, about 1 minute.
Serve immediately, garnished with extra Parmesan cheese if desired, and enjoy the warm, silky texture and comforting fall flavors in every bite.
