In a large pot, bring salted water to a rolling boil over high heat. Add the rotini pasta and cook for about 8–10 minutes until al dente, stirring occasionally to prevent sticking. Drain the pasta and cool it quickly under cold water.

Chop the fresh broccoli into small, bite-sized florets and finely dice the red onion. Combine both in a bowl and set aside.

In a medium mixing bowl, combine mayonnaise, sugar, white vinegar, salt, and pepper. Whisk until smooth and creamy, adjusting seasoning as needed.

Pour the dressing over the cooled rotini and gently fold until evenly coated.

Toss in chopped broccoli, bacon, cheddar cheese, red onion, cranberries, and walnuts, mixing until ingredients are well incorporated.

Cover and refrigerate for at least 1 hour to let flavors meld. Stir gently before serving.