Process bread in a blender or food processor until finely ground. Place in a heavy-duty zip-top plastic bag. Add flour and next 5 ingredients.
Combine buttermilk and 1/4 cup lemon juice; brush mixture on both sides of chicken. Place half of chicken in bag; shake to coat. Arrange chicken on a lightly greased rack in a broiler pan.
Repeat procedure with remaining chicken. Sprinkle with any remaining breadcrumb mixture. Stir together butter and 1 tablespoon lemon juice, and drizzle evenly over chicken.
Bake at 375° for 45 to 50 minutes or until done.