Rinse and chop the broccoli into bite-sized florets. Optionally, blanch in boiling water for two minutes and shock in ice water to preserve color.

In a medium bowl, whisk together mayonnaise, cider vinegar, and sugar until smooth.

In a large bowl, combine the broccoli, raisins, sunflower seeds, and red onion.

Pour the dressing over the salad ingredients and gently fold until evenly coated.

Cover and chill for at least one hour to enhance flavors before serving.