Wash and chop broccoli into uniform, bite-sized pieces. If using frozen broccoli, thaw completely and pat dry with paper towels to remove excess moisture.

Cook bacon until crispy, then drain on paper towels. Once cooled, crumble into small pieces. Save a few larger pieces for garnish if desired.

Whisk together mayonnaise, apple cider vinegar, sugar, salt, and pepper until smooth. Taste and adjust seasoning as needed.

In a large mixing bowl, combine chopped broccoli, diced red onion, cranberries, and sunflower seeds. Pour the dressing over the mixture and toss gently until everything is evenly coated.

Cover and refrigerate for at least 30 minutes before serving. Add crumbled bacon just before serving to keep it crispy.