Heat the olive oil in a large pot or Dutch oven over medium heat.
Add the chopped onion and bell peppers. Cook until softened, about 5 to 7 minutes.
Add the minced garlic and cook for 1 minute until fragrant.
Add the cubed butternut squash, chili powder, cumin, oregano, and cayenne pepper (if using). Stir well to coat the vegetables with the spices, cooking for 2 minutes.
Pour in the crushed tomatoes, black beans, kidney beans, corn, and vegetable broth. Stir everything together.
Bring the mixture to a boil, then reduce the heat to low, cover the pot, and simmer for 20 to 25 minutes, or until the butternut squash is tender. Stir occasionally.
Taste the chili and adjust seasoning with salt and pepper as needed.
Serve hot with your choice of toppings.
Notes
For a deeper flavor, roast the butternut squash cubes before adding them to the pot.
If you prefer a creamier texture, mash about one cup of the chili against the side of the pot before serving.