During the middle portion of the dance contest when the sedative-laced brownies have been handed out, Dee is seen dancing with one in her left hand (15:45), then after Rickety-Cricket is wheeled out by Frank, the camera cuts back to Dee, then over Mac's right shoulder where the brownie suddenly disappears from her left hand with no explanation (16:04), then just as suddenly, a few seconds later (16:11) it reappears in her left hand while she is still dancing.
Since Charlie doesn't actually own the bar, it would be impossible for him to legally nominate it as a prize in a competition.