Vegetarian Udon Noodles with Peanut Sauce

Name: Vegetarian Udon Noodles with Peanut Sauce
Ingredients: 8 ounces Japanese udon noodles; 1 (16 ounce) package firm tofu, drained; 1.5 cups shredded cabbage, or more to taste; 1 cup shredded carrot; 1 small sweet red pepper, seeded and cut into thin strips; 2 scallions, or more to taste, thinly sliced; 0.5 cup vegetable broth; 6 tablespoons natural peanut butter; 2 tablespoons brown sugar; 2 tablespoons soy sauce, or more to taste; 1 tablespoon rice vinegar; 4 cloves garlic, minced; 1 (1 inch) piece fresh ginger, peeled and minced; 0.25 teaspoon cayenne pepper