Combine the flour, egg, and breading mixtures in 3 separate shallow pans. (Be sure to beat the eggs until very frothy, this ensures they’re light/airy and not too dense.)
Slice the chicken in half lengthwise to create 2-3 thinner slices. Cover with plastic wrap and use the textured side of a meat mallet to pound it to ½ inch thick. (Thin is key here.) Pat dry. Sprinkle each side lightly with salt/pepper.
Dredge completely in the flour mixture, working the flour into every nook and cranny of the chicken. Tap off excess.
Dip the chicken in the egg mixture until just coated, use your fingers to slide off excess. (Too much egg left on the chicken can bleed through the breading, which will make it less crispy.)
Coat the chicken generously in the breadcrumbs.
Heat oil over medium-high heat. Once glistening, add the first batch of chicken, don’t overcrowd the skillet. Brown on each side for 3-4 minutes, until golden. If the oil gets too hot, adjust it down slightly, and adjust it up again later if needed.
Remove chicken with a slotted spatula and set on a wire cooling rack. Repeat with remaining chicken.
Transfer the chicken to a large, light colored baking sheet. (Dark baking sheets attract more heat and can cook the chicken too quickly.)
Top with marinara sauce and mozzarella cheese.
Bake uncovered for 12 minutes. Broil at 425° for 1-2 minutes at the end if you’d like to brown the top a little more, watch it closely during this time.
Garnish with fresh parsley and serve with spaghetti and garlic bread with cheese. Ensure the internal temperature is 165° prior to serving.
Notes
Pro Tips
Make sure the oil is sufficiently heated before you add the chicken, this ensures the breading stays intact as it should fry immediately. Otherwise it can get soggy and won't be as crispy.
I like to bread 1-2 pieces of chicken at a time instead of all at once. While the first batch fries, I'll bread the next batch. This keeps things extra crispy.
Small adjustments to the heat, up/down, may be needed throughout frying to ensure it doesn't get too hot or too cool.
Low Moisture, Whole Milk mozzarella will melt the best. Shred it from a block, it will melt and taste best that way.