Pour enough oil into a large Dutch oven or pot to come about 1 1/2 inches up the sides and fit the pot with a deep-fry thermometer. Bring the oil to 375 degrees F over medium-high heat.
Meanwhile, mix the marinara, creme fraiche and red pepper flakes in a medium microwave-safe bowl. Microwave for 1 minute until warm. Cover and set aside until ready to use.
Place a wire rack inside of a baking sheet. Set up a standard breading station with 3 wide, deep plates (or pie plates). Place the flour and 1/2 teaspoon salt in one plate. Mix the panko, plain breadcrumbs, Parmesan, garlic powder, onion powder, Italian seasoning, 1 teaspoon salt and a generous amount of black pepper into the second plate. Whisk the eggs into the third plate.
Take each mozzarella stick through the breading procedure: first in the flour, then the egg and then the panko mixture, then repeat in the egg and panko mixture again for a double breading. Transfer to the wire rack.
Working in batches, carefully drop 4 to 5 sticks into the oil and fry without touching until they are a deep golden brown and you can see some cheese starting to melt, 1 to 1 1/2 minutes. Remove with a slotted spoon or spider to a paper towel-lined baking sheet. Serve immediately with the sauce on the side.