Custard - just whip up your basic instant pudding, using just a tad more milk that usual so it's not super-thick. I used vanilla for authenticity, but you can use any flavor you like.
Bake (or buy) a pound cake loaf and let it cool. (I usually make the kind in the box - Betty Crocker?)
While it's cooling, crush 2 packages of graham crackers until you've got fairly fine crumbs, and put them in a shallow bowl for later
Cut pound cake into 1" or thicker slices
Cut each slice into 1" or wider strips
melt 1 stick of butter in a shallow bowl
dip each cake strip into butter, then roll in graham cracker crumbs (you may need to melt more butter before you're done with the whole loaf, but I can't remember)
let your fish fingers sit for a minute to set up, and serve with a bowl of custard for dipping
Pretty easy, right? and tasty, too. I thought I'd have to brown them in the oven, but just letting them sit a minute sets up the butter & crumbs just right.