Can I just roast halves of butternut squash in the oven and scoop out (rather than cubing which I hate doing)?

Leave the seeds in, too. They add to the flavor. (Then scoop them out when you make the soup)

I also do that all the time. At someone's suggestion, I even put the whole squash in the oven, just pricking it so it wouldn't explode. But I found it was more difficult to remove the seeds and gunk after cooking than before.

There's a Thomas Keller recipe that Amanda once wrote about in the NY Times that calls for half roasted and half cubed squash, so if you want to practices layering of flavor, you could try that http://www.nytimes.com/2004/12/12/magazine/12FOOD.html?pagewanted=print&position=&_r=0 (His soup is great but not so wonderful that I've made it a standard.)

I've never made this particular recipe (though it looks great, so I will!,) but I make lots of other pureed butternut squash soups - and I ALWAYS roast it in the oven, instead of peeling/cubing. It does add a deeper flavor, plus it's way easier. (As a klutz, I find wrestling a butternut squash with a knife and peeler is begging for trouble;)

I think that would work just fine! You may get a deeper flavor from the roasting, which will caramelize the squash -- but that's almost never a bad thing. Let us know how it turns out if you try it!