Which Alton brown fruitcake recipe did they use on the Iron Chef competition?

Unfortunately, there is no publicly available information about the specific Alton Brown fruitcake recipe used on the Iron Chef competition. The show never explicitly mentioned the recipe, and Alton Brown hasn't shared a specific one he used for the competition.

However, it's likely that the recipe used in the show was based on Alton Brown's general approach to fruitcake, which emphasizes:

* Flavor and moisture: He often uses spices like ginger, cardamom, and cloves to add complexity, and incorporates plenty of butter and liquid to keep the cake moist.

* High-quality ingredients: He uses good-quality fruit, nuts, and spices, and often makes his own candied fruit for a superior flavor.

* Proper baking technique: He emphasizes using a low and slow baking method to ensure even cooking and prevent the cake from becoming dry.

If you're looking for an Alton Brown-inspired fruitcake recipe, you can find many options on his website and in his cookbooks. These will likely be close to what he used in the Iron Chef competition.