Bake the bacon at 400°F for 18 to 22 minutes, then drain on paper towels and cool completely before crumbling.

Fill a large bowl with cold water and 1 cup white vinegar. Soak the broccoli for 5 minutes, then lift out, rinse, and dry thoroughly.

Cut the florets and thin stems away from the thick central trunks. Divide the usable broccoli into two piles.

Pulse one pile of broccoli in a food processor until finely chopped. Hand-chop the second pile into small bite-size pieces.

Combine both batches of broccoli in a large mixing bowl. Add the crumbled bacon, green onions, raisins, and sunflower seeds. Toss lightly.

In a separate bowl, whisk together the mayonnaise, sugar, and white vinegar until smooth.

Pour the dressing over the broccoli mixture and stir well to coat.

Cover and refrigerate for at least 2 hours, preferably 4 hours. Stir again before serving.