Step 1: Preheat your oven to 400°F (200°C). On a large baking sheet, toss the cubed butternut squash with olive oil, nutmeg, salt, and pepper until evenly coated.
Step 2: Roast the squash for 25-30 minutes, tossing halfway through, until the edges are golden brown and the squash is tender.
Step 3: While the squash is roasting, bring a large pot of salted water to a boil. Cook the pasta according to package directions until al dente. Reserve 1 cup of pasta water before draining.
Step 4: In a large skillet or pan, melt the butter over medium heat. Continue cooking, stirring frequently, until the butter stops foaming and turns a deep amber color with a nutty aroma.
Step 5: Immediately add the fresh sage leaves to the brown butter. Fry for 30-60 seconds until they become crisp, then remove the skillet from heat.
Step 6: Add the cooked pasta and roasted squash to the skillet with the brown butter and sage. Toss gently to combine.
Step 7: Add the Parmesan cheese and a splash of the reserved pasta water, tossing until a glossy sauce forms that coats the noodles.
Step 8: Serve immediately, garnished with toasted pecans and an extra sprinkle of Parmesan if desired.