Line a rimmed baking sheet with parchment paper and set it to the side.
In a small shallow bowl mix the flour, arrowroot powder, salt, pepper, and garlic powder. In a second shallow bowl, whisk the eggs. In a third shallow bowl, add the Italian breadcrumbs.
If using a block of cheese: cut the block into 3-inch long x ½ inch thick sticks. I had 14 pieces. If using string cheese, cup the 12 sticks in half so you have 24 mozerella sticks.
Roll each cheese stick in the flour (shake off excess). Then dip it in the egg mixture (letting excess egg drip back into the bowl). Then roll and press in the bread crumbs. Place the finished mozzarella sticks on the lined baking sheet.
Freeze the mozzarella sticks for at least 2 hours or until frozen solid.
Oven-Baked: Preheat oven to 400°F. Lightly spray the tops of the frozen mozzarella sticks with the oil or avocado oil spray. Bake 8 - 10 minutes until crispy and golden. Keep an eye on them as they back to make sure the cheese doesn't melt out!
Air Fry: Preheat your air fryer to 390°F. When ready, line the bottom of the basket with parchment paper, place the mozzarella sticks in a single layer across the bottom (no overlapping), and spray them with a little olive oil spray or cooking spray. Air fry for 5 - 7 minutes or until crispy. Check at the 5-minute mark to make sure the cheese is not melting out.
Serve mozzarella sticks immediately with marinara sauce.