This prank is incredibly funny, it may take some time but its worth it!! Make any cookie recipe and put HEAPS of salt in some of the cookie mixture. Make some that is "normal" for your buyers to try! You can also use something else like chilli or cayenne pepper. I have also done mustard powder it's funny (pranked my friends real good)! Next sell your cookies to your family or in the neighborhood if you have lots of guts.