425 is going to leave you with chicken fingers with the centers still frozen and the outside like molten lava. Drop the temp to 350 or 375 and cook them longer, like 25-30 mins.
Make sure you cook them well so you don't get saspurella or some shit.
http://www.youtube.com/watch?v=hlepAWhCTrgquoted for posterity.
god knows that noone wants sasparilla soda when they don't cook their chicken fingers properly.