Cut the fresh mozzarella block into 3/4-inch thick sticks, about 3 inches long. Place the sticks on a parchment-lined tray and freeze for at least 1 hour.
In a shallow bowl, place the all-purpose flour.
In a second shallow bowl, whisk together the eggs and water until well combined.
In a third shallow bowl, combine the breadcrumbs, grated Parmesan cheese, garlic powder, dried Italian seasoning, salt, and black pepper.
Remove the mozzarella sticks from the freezer. Working one at a time, dredge each stick in the flour, shaking off excess.
Dip the floured mozzarella stick into the egg wash, then coat thoroughly with the breadcrumb mixture. For extra crispiness, repeat the egg wash and breadcrumb coating once more.
Place the coated mozzarella sticks on a parchment-lined tray and freeze for at least 30 minutes before frying.
Heat about 2 inches of vegetable oil in a deep skillet or pot to 350°F (175°C).
Fry the mozzarella sticks in batches for about 1 to 2 minutes, turning occasionally, until golden brown and crispy. Do not overcrowd the pan.
Using a slotted spoon, transfer the fried mozzarella sticks to a paper towel-lined plate to drain excess oil.
Serve immediately with warm marinara sauce for dipping.