(FORTUNE Small Business) – When their 8-year-olds insist on a birthday cake in the shape of a Harry Potter quidditch arena or NASA's Saturn V rocket, the well-heeled party hosts of Baltimore call Duff Goldman. The owner of Charm City Cakes does make classical white wedding cakes, but his specialty is the oddball: a cake shaped like Wrigley Field or a chaise longue or the family dog. Goldman, 30, makes 12 to 15 cakes a week--up from five a year ago--at prices of $175 for a simple square to $20,000 for a massive, mechanized cake with edible moving parts. In 2002 he made a cake to resemble a piece of rare black Wedgwood china for Hillary Clinton. A former graffiti artist with degrees in philosophy and physics, Goldman estimates that he has baked 3,000 cakes since opening the business five years ago. Last month he taped his national television cooking debut in a Food Network Halloween cake contest, which airs in October. He promises "blood and guts." Lately, he says, he has had to turn away some $100,000 worth of business every month. "Magic doesn't come from an assembly line," he points out. --JULIE SLOANE