Preheat oven to 400ºF. Coat a large baking sheet with cooking spray.
In a shallow dish, combine flour, salt and pepper; mix well with a fork to combine. Place egg whites and breadcrumbs in separate shallow dishes. Add zucchini to flour mixture; turn to coat. Next, add zucchini to egg whites; turn to coat. Last, add zucchini to breadcrumbs and turn to coat.
Place coated zucchini on prepared baking sheet in a single layer and coat with cooking spray; bake until golden brown, flipping once or twice, about 40 minutes.
Meanwhile, in a small bowl, whisk together mayonnaise, honey and mustard; serve with zucchini sticks. Yields about 6 sticks and 1 tablespoon dip per serving