To make the tofu sour cream, simply place all ingredients in a blender or a food processor and blend till smooth.
For the most flavorful chili results, heat the olive oil in a large sauté pan over medium heat. Add the onions and celery and a pinch of salt, to get the onions sweating. Sauté for about 5 minutes, or until the onions are soft and clear. Add the garlic and cook for about 1 minute, stirring frequently. Add 1/4 cup water, the tomato paste, the chipotle en adobo, the chili powder, cumin, coriander, smoked paprika, cinnamon, salt, and cayenne. Allow it to cook for one more minute, stirring to incorporate all of the ingredients.
Add the broth, black beans, squash, diced tomatoes and their juices, and quinoa to your slow cooker. Add the cooked onion, garlic, and spice mixture. Stir everything to combine well. Cook on low heat for 6 hours. Before serving, give the chili a good stir and add some additional vegetable broth if you'd like it to be less thick. Taste, adjust seasonings, and serve with toppings of choice.
Alternately, you can simply add all of the ingredients to the slow cooker and cook for 6 hours on low. If you have the time, browning the onions and garlic will give you most flavor. See note for stovetop option!