Preheat your griddler or panini press on high or sear.
In a shallow dish, pour the breadcrumbs in it, add a little salt and pepper, mix it up. Set aside.
In a ziploc bag, pound out the chicken tenderloins, gently, until they're flattened.
Cover the chicken in breadcrumbs and cook in a skillet on medium high heat until they're cooked through & browned on both sides.
Assemble your panini: butter the slices of bread on the outside (the sides that will be touching the panini grill). On one slice of bread, place the chicken on it and spread a medium thick layer of marinara sauce and put the basil on top, on the other slice of bread, sprinkle mozzarella cheese on top. Put the 2 halves together and put on panini press for 5 minutes or until the cheese is melted and the bread has nice grill marks on it.
Remove from panini press or griddler and cut in half and serve hot :)