Pre-heat your oven to 400°F and line a large, rimmed baking sheet with parchment paper or a Silpat™ baking mat. Set aside.

Add butternut squash, red onion, and garlic cloves to a large bowl. Drizzle with the olive oil and season with salt and black pepper, to taste. Gently toss to combine and transfer to the prepared baking sheet. Spread into a single layer without overcrowding.

Place the vegetables in the pre-heated oven and roast for 25-30 minutes, turning halfway through, or until vegetables are fork tender and golden brown.

While the butternut squash mixture is roasting, prepare the orecchiette according to package instructions. Once the pasta is al dente, reserve one cup of the cooking water prior to draining. Return pasta to the pot and set aside.

Remove the roasted vegetables from the oven and carefully transfer to a food processor or a high-speed blender. (Do not overfill). Cover and blend until completely smooth. Add a little of the reserved cooking liquid, if necessary.

Temper the heavy cream by stirring a one or two tablespoons of the hot butternut squash puree to it before adding to the blender. Add the mascarpone cheese and blend until smooth.

Pour the creamy butternut squash sauce into the pot with the pasta and stir to combine. Add some of the reserved cooking liquid to thin out the sauce, as needed.

Stir in the butter, Parmesan cheese, and fresh thyme leaves. Season with additional salt and black pepper, to taste, and serve immediately topped with additional Parmesan cheese, if desired. Enjoy!