Preheat the oven to 425°F. If you're using a baking stone/steel, place the stone/steel in the bottom third of the oven before you start preheating.
In a baking dish, toss together the squash, onion, bell pepper, garlic, olive oil, chili powder, cinnamon, and cumin. Season with some salt and pepper and roast for 30 to 35 minutes, stirring occasionally, or until the squash is very tender.
Meanwhile, in a medium saucepan, bring the diced tomatoes and chiles to a boil, then reduce the heat to low and simmer, uncovered, until most of the liquid has evaporated, 5 to 7 minutes. Stir in the Worcestershire sauce and remove the pan from the heat. When the vegetables are done roasting, add them to the sauce along with the corn, beans, and balsamic vinegar. Mix well, give it a taste, and add more salt, pepper, and balsamic as needed.
Increase the oven temperature to 500°F (if using a baking sheet) or as high as it will go (if using a baking stone/steel). If you’re using a baking stone or steel, switch the oven to Broil on high as soon as it reaches the higher temperature.
Stretch or roll out your dough to a 12- to 14-inch circle, then transfer it to an oiled or parchment-lined baking sheet or a lightly floured pizza peel (if using a baking stone/steel).
Spread the chili mixture evenly over the dough, leaving a ½-inch border all around, and scatter the cheese on top. Brush the edges of the dough with a little olive oil.
Transfer the pizza to the oven and bake until the crust is golden and spotted on the bottom—8 to 10 minutes on the baking sheet, 6 to 8 minutes on the baking stone/steel. Remove the pizza from the oven.
Let the pizza rest for a few minutes, then sprinkle with the scallions. Slice and serve with a small bowl of sour cream, if using.