There are many versions of this out there, this one is a Frankenstein of my favorite soups, plus some of my own touches.
Please note, that while I am normally obsessive about buying ingredients in the least expensive way, I refuse to cut a butternut squash because frankly my knives aren't sharp enough and I like all of my limbs so I spring for the pre-cut stuff.
Also, I think that the quality of your ingredients is key, I'm addicted to the apple cider from Honey Pot Hill Farms in Stow, MA and I cannot recommend it enough. It is unpasturized so it only lasts a week, which was part of the inspiration for this soup.
1 package of cubed butternut squash
Olive Oil for coating
2 Tbsp butter
1 small yellow onion, diced
2 normal sized apples (only 1 if it's the size of a softball), diced
1 cup apple cider
32 ounces vegetable broth
1 Tbsp red wine vinegar
Sour Cream to garnish
Preheat your oven to 375, coat butternut squash with olive oil, sprinkle with salt
Roast for 30 minutes
When done remove from oven and set aside
Melt butter over medium heat (you could brown the butter but I inevitable burn so I didn't)
When butter is melted add onion and cook for 5 minutes stirring occasionally
Add apple and cook an additional 3 minutes
Stir in butternut squash and apple cider
Let simmer for 5 minutes
Add vegetable broth and splash of vinegar
Bring to a boil, then turn heat to low, cover and cook an additional 8-10 minutes
Puree soup with a handheld mixer or in batches in a food processor
Serve with sour cream, add about a tablespoon to each cup of soup (don't overdo it on the sour cream or you'll kill it, but don't omit this or you'll have too sweet of a soup, hows that for directions?)
I served mine with focaccia from King Arthur Flour's website (more on this at a later date). The recipe can be found here, the only change I made was subbing 1/3 of the AP flour for bread flour. It's the first time I've made this recipe and I will definitely be repeating it. In fact, I will be using the leftovers to make pizza tomorrow night!
PS My 2 year old daughter loved this recipe and kept calling it apple sauce soup, so it's a multi-generational hit!