In a large bowl, combine the broccoli florets, cauliflower florets, shredded carrots, red onion, sunflower seeds, raisins, and crumbled bacon if using. Toss to mix the ingredients evenly.
In a separate small bowl, whisk together the mayonnaise, apple cider vinegar, honey, salt, and black pepper until smooth.
Pour the dressing over the broccoli mixture and toss until all the vegetables are well coated.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld.
Serve chilled or at room temperature.