Preheat oven to 400°F (200°C). Toss cubed butternut squash and garlic cloves with olive oil, salt, and pepper on a baking sheet. Roast for 20 to 22 minutes until tender and caramelized at the edges.

Bring a large pot of generously salted water to a rolling boil. Cook fettuccine pasta until al dente (approx. 9 to 11 minutes). Reserve 1 cup of starchy pasta cooking water before draining.

Transfer hot roasted squash and soft roasted garlic into a high-powered blender. Add vegetable broth, heavy cream, nutmeg, sea salt, and black pepper. Blend on high for 60 seconds until completely silky, luxurious, and smooth.

In a wide skillet, melt 2 tablespoons of butter over medium heat. Add fresh sage leaves and fry for 60 to 90 seconds until crisp and fragrant. Transfer crispy sage leaves to a paper towel, leaving the sage-infused brown butter in the skillet.

Pour the blended butternut squash puree directly into the skillet with the sage butter. Simmer over medium-low heat for 2 minutes to heat through.

Add drained fettuccine and grated Parmigiano-Reggiano into the skillet. Toss continuously with tongs for 2 minutes, splashing in reserved pasta water as needed until a glossy, clinging orange sauce envelops every strand.

Twirl pasta into wide shallow bowls. Top with crispy fried sage leaves, toasted chopped pecans, shaved parmesan ribbons, and freshly cracked black pepper. Serve immediately.