Heat the oil in a large soup pot over medium heat.
Add the onion and bell pepper and cook, stirring occasionally, until tender, 5-10 minutes.
Add the garlic, cocoa, chili powder, smoked paprika, cumin, cinnamon, cayenne, and salt and cook, stirring occasionally, until fragrant, 5 minutes.
Add the bay leaf, winter squash, beans, tomatoes, and vegetable broth. Increase the heat to medium high and bring to a simmer.
Lower the heat to maintain a gentle simmer, cover the pot partially, and cook, stirring frequently, until the squash is very tender and the chili has thickened to a chunky consistency, 30-45 minutes.
Serve bowls of chili topped with a handful of tortilla chips, a few slices of avocado, a spoonful of sour cream, a handful of cheese, and a pinch of scallions.
The chili keeps well, refrigerated airtight, for up to several days.
