Place panko crumbs in a Ziploc bag and use a rolling pin or mallet to crush until you have fine crumbs.
Pour crushed panko into a shallow dish and add Italian seasoning, parsley, garlic powder, pepper, and salt and stir to combine.
In a separate, shallow bowl, crack 2 large eggs and beat with a whisk or the tines of a fork until scrambled.
Pour all-purpose flour in yet another shallow bowl.
If using a mozzarella block, cut widthwise into 15 sticks.
Working with one at a time, dip the stick in the flour and shake off any excess flour. Then dip in the beaten egg and let any excess drip off. Finally, dip in panko crumb mixture, making sure the entire cheese stick is coated with panko.
Place a wire cooking rack on a baking sheet and place breaded mozzarella sticks on rack. Once all sticks have been dipped, transfer to the freezer and chill for at least one hour. If you are chilling for longer than 1 hour, after 1 hour remove from freezer and place in an airtight container then return to freezer.
While sticks are still in the freezer, fill a medium-sized saucepan 3” deep with vegetable oil. Attach a thermometer to the side and make sure it is suspended about halfway into the oil (and that it is not touching the bottom of the pot). Heat oil over medium heat until you reach a temperature of 350F (175C) then remove sticks from freezer.
Fry sticks, 2 at a time, until golden brown (about 1 minute) then remove to a paper towel-lined plate to cool. Make sure oil returns to temperature before frying next batch.
Enjoy while still warm dipped in warmed marinara sauce.