A customer at work (thanks Jen!) made these and then gave me the recipe (which you can find
here). I've made them twice now and have been put into chocolate shock both times. I've found that whisking for a full 15 minutes as recommended if fairly outrageous and unnecessary. Just make sure your eggs are at room temperature first. Baking them towards the lower end of the recommended 8-10 minutes and allowing them to cool and dry on racks completely will result in a more moist and gooey interior, as will chopping the dark chocolate coarsely instead of fine.