Cut the mozzarella cheese into sticks about 1/2 inch thick.
Place the flour in a shallow bowl. In a second bowl, beat the eggs with water. In a third bowl, add the breadcrumbs, garlic powder, and onion powder and mix to combine them.
Dredge each mozzarella stick in the flour, shaking off any excess.
Dip the floured stick into the egg mixture, letting the excess drip off.
Roll the stick in breadcrumbs, pressing gently to adhere.
For a thicker crust, repeat the egg and breadcrumb steps.
Place the breaded sticks on a plate and freeze for at least 30 minutes.
Heat vegetable oil in a deep fryer or heavy pot to 350°F.
Fry the sticks in batches for 1–2 minutes, until golden brown.
Drain on paper towels and serve hot with marinara sauce.