Cut each cheese stick in half to create 24 pieces. Place cheese pieces on a plate and freeze for at least 1 hour until frozen. These can be stored for several days in the freezer until ready to use. Wrap them in plastic wrap, once frozen.
Preheat oven to 400 degrees. Line a baking sheet with foil and coat with cooking spray. Set aside.
In a small bowl, beat the egg. Place flour in another small bowl. In a third small bowl, add panko bread crumbs, garlic powder, salt, and pepper. Mix well.
To assemble mozzarella sticks: Dip frozen sticks in flour, shaking off excess, then into egg, then finally coat with panko crumbs. Repeat steps to coat all of them.
Place all coated sticks on the baking sheet. Spray the tops with cooking spray.
Bake for 5 minutes, turn over and spray with a little more cooking spray. Bake an additional 4-5 minutes until heated but NOT melted. In fact, be sure to keep an eye on them so they don’t melt!
Remove from oven and place on a plate. Serve with pizza sauce on the side. Refrigerate any leftovers. They will keep for several days. To reheat, either zap in microwave for a few seconds or place on a baking sheet and heat in a 400-degree oven until warm but not melted.