Cook the Bacon: Chop bacon into small pieces and cook in a skillet over medium heat for 8-10 minutes until crispy. Drain on a paper towel-lined plate.

Blanch the Broccoli: Bring salted water to boil, add broccoli florets, and blanch for 3 minutes. Transfer to ice water to stop cooking.

Drain and Dry the Broccoli: After cooling, drain the broccoli and pat dry to avoid watery dressing.

Mix the Dressing: Whisk together mayonnaise, vinegar, onion, sugar, and optional raisins until smooth.

Combine Broccoli and Dressing: Toss cooled broccoli with the dressing until evenly coated.

Chill the Salad: Cover and refrigerate for at least 1 hour to meld flavors.

Add Crunch at Serving Time: Fold in crispy bacon and sunflower seeds just before serving.