Bring a large pot of salted water to boil and cook your pasta according to package directions for al dente pasta. Drain, return to the pot, and set aside.
Meanwhile, add the squash to a small sauce pot, cover with water and boil for 8 minutes, or until easily pierced with a fork. Then drain it and add to your blender, along with all remaining sauce ingredients, starting with ¾ cup of the milk. Blend until smooth, and add more milk if needed for a thinner consistency.
Then pour the sauce over the pasta, mix well, and serve with any garnish you like. (Reserve 1-2 cups of the sauce if you want to add more on top of each bowl for serving.)
Notes
Salt your pasta water. Make sure to add enough salt to your pot of water for the best texture and flavour. Here’s a handy guide to help you salt your water perfectly each time.If you do not have a powerful blender, add the cashews to the same pot with the squash and boil until the squash is cooked. This will soften the cashews and help them blend more smoothly.You may need more or less milk, depending on the size of your squash.As the pasta sits with the sauce, it will continue to absorb it. So, if you plan to have leftovers, reserve a cup of the sauce in a separate container before mixing it into the pasta. Add the reserved sauce to a pan with the leftover pasta when reheating to return it to a creamy state.Leftovers keep refrigerated for 3-4 days. You may freeze the sauce for up to 3 months in an airtight, freezer-safe container. I don't recommend freezing pasta as it alters the texture.