Preheat the oven to 425 degrees F and coat a large, rimmed baking sheet with nonstick spray.

Spread the sliced zucchini onto paper towels and lightly pat dry. Let rest on the towels while preparing the coating.

In a wide, shallow dish, combine the Panko, flour, Parmesan, salt, onion powder, and pepper.

In a separate bowl, whisk the egg whites until lightly foamy.

Working with five or six zucchini fries at a time, toss them in the egg whites to coat evenly. Shake off any excess egg white.

Transfer the zucchini to the Panko mixture and coat them, pressing on lightly to ensure adherence. Arrange the zucchini on the baking sheet, making sure they do not touch.

Lightly coat the exposed sides of the zucchini with cooking spray.

Bake for 10 minutes, then remove from the oven and coat again with baking spray.

Return to the oven, rotating the pan 180 degrees, and continue baking for an additional 10 minutes until crisp and golden.

While the zucchini bakes, prepare the dipping sauce by whisking together the Greek yogurt, basil, garlic, Worcestershire, salt, and pepper. Adjust seasoning as desired.

Serve the fries immediately with the dipping sauce.