Bring a large pot of salted water to a boil and cook pasta according to package instructions.
Add the cubed butternut squash and cashews to a pot and cover with water. Let boil until the squash is fork tender, about 20 minutes.
Add the diced onion and minced garlic to a pan and saute with 1 tablespoon of olive oil for about 5-7 minutes or until lightly golden brown.
Drain the butternut squash and cashews and add to a high speed blender with all ingredients aside from the cheese but including the onion/garlic.
If you're using dairy free cheese (I like violife cheddar shreds) it can take a while to melt, so if you notice it is still chunky after 10 minutes (be sure to stir very frequently), transfer back to a blender and blend until smooth.
Blend until completely smooth.
Transfer to a pot and stir in the cheese. Let melt over low heat, stirring occasionally.
Once melted, stir in the cooked pasta until well combined. Serve and enjoy!
It will seem very saucy at first, but the pasta will absorb some of the sauce, especially if you're using a gluten free pasta. If you prefer it less saucy, just pour less on top!