Spicy Butternut Squash Chili

Name: Spicy Butternut Squash Chili
Ingredients: 2 tablespoons olive oil; 1 medium onion, chopped; 2 tablespoons minced garlic; 1 pound ground beef; 1 pound cubed butternut squash; 1 (16 ounce) package frozen mixed vegetables; 2 (10 ounce) cans diced tomatoes with green chile peppers; 1 (14.5 ounce) can diced tomatoes; 1 cup chicken broth; 1 (7 ounce) can chipotle peppers in adobo sauce, chopped; 1 (6 ounce) can tomato paste; 1 tablespoon chili powder; 1 tablespoon ground cumin; 1 teaspoon garlic powder; 0.5 teaspoon cayenne pepper, or to taste; 1 tablespoon brown sugar, or to taste