In a medium-sized bowl, combine the mayonnaise, apple cider vinegar, vegetable oil, salt, ground black pepper, and sugar; mix well.
Remove the broccoli florets from the stem and separate the florets into small bite-sized pieces.
Add the broccoli florets to the dressing; mix well. Add the cheddar cheese, mozzarella cheese, and bacon bits; mix well.
Cover and refrigerate for at least 30 minutes before serving.
Recipe Tips
Dry the broccoli thoroughly. Any water left on the florets will dilute the dressing and collect at the bottom of the bowl. After rinsing, pat the broccoli dry or let it air-dry for a few minutes on a clean kitchen towel.
Chill for at least 30 minutes, but longer is better. The salad reaches peak flavor four to five hours after mixing, once the sugar has dissolved, the dressing has absorbed into the broccoli, and the bacon has softened just slightly. If time allows, make it the morning of your event and refrigerate until ready to serve.
Stir before serving. The dressing naturally settles toward the bottom of the bowl as the salad sits. A quick stir redistributes everything and freshens the presentation.
Cut the florets small. Smaller florets mean more surface area for the dressing to coat and easier eating with a fork or spoon. Aim for pieces no larger than about an inch across.