In a mixing bowl, combine the softened cream cheese and mayonnaise. Mix until smooth. Then, add in the shredded cheddar cheese, shredded mozzarella cheese, garlic powder, and seasoned salt. Stir until everything is well incorporated.
Take two slices of French bread and spread a generous amount of the cheese mixture on one side of each slice. Place the slices together, cheese side facing in, to form a sandwich.
Preheat your skillet or griddle over medium heat.
Once the skillet is heated, place the assembled sandwich on it. Cook for about 3-4 minutes or until the underside is golden brown.
Carefully flip the sandwich over, and continue to cook for another 3-4 minutes, or until the other side is golden and the cheese is melted.
Remove the sandwich from the skillet. Let it cool for a minute before slicing it in half. Serve immediately.
