Combine the stick of butter, granulated garlic, parsley, and a pinch of salt in a small bowl. Mix well. Spread a thin layer of the butter mixture onto each slice of bread. Place two slices of mozzarella onto half of the bread slices (see pictures). Close the sandwiches.
Prepare 3 shallow bowls, one with the flour, one with the eggs, and one with the breadcrumbs. Beat the eggs. Season the breadcrumbs with a pinch of salt. Dredge each sandwich really well through the flour, eggs, and then breadcrumbs.
Heat 2 (12”) fry pans over medium-low heat. Add 2 tablespoons of butter to each pan and let melt. Once the butter is hot, add 2 of the sandwiches to each pan. Cook until golden on one side, about 3 minutes. Carefully flip the sandwiches. Cook for another 3 minutes until golden.
Drizzle the sandwiches with olive oil and cover the pans, leaving the lids cracked slightly so steam can escape. Cook for 1-2 more minutes, or until the cheese has fully melted.
Uncover the sandwiches and transfer them to a cutting board. Slice in half. Season them with a pinch of salt. Serve with warm marinara sauce on the side and a sprinkle of grated parmesan over top.