Unwrap the string cheese and cut each piece in half crosswise. Place pieces on a parchment-lined baking sheet and freeze 5 minutes.

Meanwhile, to a medium shallow bowl, add the cornstarch. In a second shallow bowl, beat together the eggs and 1 tablespoon water. In a third shallow bowl, combine the bread crumbs, oregano and onion powder. Season all three bowls with salt and pepper.

Remove mozzarella sticks from freezer, reserving baking sheet. Dip each mozzarella stick in cornstarch, making sure to coat all sides and ends completely. Shake off excess cornstarch, then dip into egg mixture. Let excess egg drip off, then dredge in bread crumb mixture, coating well (this helps keep melted cheese from leaking out). Place coated mozzarella sticks on prepared baking sheet and freeze for 30 minutes or until ready to cook.

When ready to cook, preheat oven to 400 degrees F. Bake frozen mozzarella sticks 7-10 minutes, turning halfway through. Serve with the warm marinara sauce.

Tip: To cook in the air fryer, coat basket with cooking spray and bake mozzarella sticks at 370 degrees F for 6 minutes, flipping once halfway through.