"Why this recipe works:These individual chocolate cakes are cooked in coffee mugs in the microwave for a nearly instant dessert. To keep our cakes from overflowing, we had to supplement bittersweet chocolate with cocoa powder; cocoa powder has less fat, which produces less steam, thus less chance of an overflow. Microwaving the cakes on 50 percent power was the key to cooking them gently, helping create a light, tender crumb, and stirring the batter halfway through ensured even cooking. Finally, a few chunks of bittersweet chocolate added to each cake created a gooey, molten center...."