Preheat the oven to 400 degrees.
Combine gluten-free bread crumbs, garlic powder, Italian seasoning, salt, and pepper in a shallow dish. In 2 more shallow dishes, place beaten eggs and gluten-free flour.
Dust each piece of chicken with flour, then dip into the beaten egg. Then coat with the breadcrumb mixture. Set aside on a baking tray while heating a large high-sided skillet with about a half-inch to an inch of olive oil.
Fry each piece of breaded chicken until golden brown on each side. You may need to cook in batches if your pan is too small to fit 4 at once.
When all pieces have been fried nicely, place them in a single layer on a greased or lined baking tray. Spoon 2-3 tablespoons of marinara on top of each, then generously top with shredded mozzarella and parmesan cheese.
Bake in the oven for 10-15 minutes until the cheese is melted and browned as you like it.