Preheat the oven to 400 degrees. Remove the seeds and pulp from the butternut then slice in half lengthwise. Place the squash halves on a lined baking sheet and drizzle the flesh with about 1 tablespoon of the olive oil. Brush the oil over the flesh of the squash then season with salt and pepper. Flip the squash over onto the lined baking sheet with the flesh facing down. Bake in the preheated oven for 40-50 minutes until fork tender. The fork should be able to very easily pierce the flesh. This can be done 1-3 days ahead of time and kept in the fridge.

While the squash roasts, bring a large pot of water to boil. Season it generously with salt. During the last 5-10 minutes of the baking time for the squash, cook the spaghetti according to the package instructions for al dente. Reserve ⅓ cup pasta water. Drain but don’t rinse the pasta!

Once the roasted squash comes out of the oven, heat your largest skillet or saucepan over medium heat. Scoop out the flesh of the roasted butternut and measure 1 1/2 cups (packed) then add it to a blender along with the cream, vegetable broth, and apple cider vinegar. Blend until very smooth and creamy. Save any extra roasted butternut squash in the freezer for another batch or use it in other recipes.

Add the remaining tablespoon of olive oil to the hot skillet. Once it shimmers, add the shallot and a pinch of salt. Cook, stirring regularly, until the shallot just begins to turn golden, about 2-3 minutes. Add the rosemary, thyme, and garlic and cook for 1 to 2 minutes, stirring continuously. Pour in the pureed butternut squash mixture and stir then reduce the heat to medium low. Season with a big pinch of salt. Cook, stirring regularly, until the sauce is heated through, then add the cooked pasta and the reserved pasta water. Toss to coat the pasta in the sauce. Season with more salt and pepper as needed.

Remove the pasta from the heat. Serve it into bowls and top with a sprinkle of roasted chopped hazelnuts, parmesan, and lemon zest.

Keep leftovers in the fridge and enjoy within 4-5 days. Reheat in the microwave or in a pot over medium low heat with a few splashes of broth, milk, or water.

I do not recommend freezing the butternut squash pasta as it tends to become mushy once thawed but you can freeze the sauce by itself! Place the sauce or any leftover roasted butternut squash in freezer-safe containers and freeze for up to 3 months. Thaw overnight in the fridge before using.