Preheat the oven to 430°F or 220°C. Line a baking sheet with parchment paper.Peel and seed the butternut squash, then cut it into 1-inch cubes.Add it to the baking sheet with olive oil, salt, and garlic powder.Toss and bake for 30 minutes, until completely soft and slightly browned.
Transfer the roasted butternut squash to a food processor (or blender) and add the ricottacheese, parmesancheese, salt, pepper, thyme leaves, and water.
Blend until you have a smooth sauce, then transfer it into a large pan.
Cook the pasta al dente in a large pot with salted boiling water. Reserve one cup of pasta water, drain the pasta and toss it in the sauce.Stir for half a minute on medium heat. Add some reserved pasta water if necessary.
Serve the butternut squash pasta with freshthymelaves, pistachionuts, and optionally a sprinkle of grated parmesan cheese.