Heat the oil in a large soup pot over medium heat. Add the onion and poblanos and cook until soft, 5 to 7 minutes. Add the garlic, cumin, and oregano and cook for 1 minute.
Add the squash, beans, tomatoes (with juice), broth, chipotle powder, and salt. Bring to a boil over high heat. Reduce the heat to medium-low and simmer until the squash is tender, 25 to 30 minutes.
Tip: To easily peel a whole butternut squash, prick it all over with a knife tip, then microwave it on high for about 2 minutes to soften the skin. Let cool slightly, then peel down to the orange flesh with a sharp vegetable peeler. To save time, buy prepeeled and chopped butternut squash from the produce aisle, or buy it frozen.