There is nothing quite as satisfying as warm chocolate cake. The following recipe from America’s Test Kitchen is fool-proof and guaranteed to produce the perfect molten chocolate cake in just ten minutes. Best of all, you don’t have to feel guilty when you indulge.
Microwave butter and chopped chocolate in large bowl, stirring often, until melted, about 1 minute. Whisk sugar, eggs, cocoa, vanilla, and salt into chocolate mixture until smooth. In separate bowl, combine flour and baking powder. Whisk flour mixture into chocolate mixture until combined. Divide batter evenly between two 11-ounce coffee mugs.
Place mugs on opposite sides of microwave turntable. Microwave at 50 percent power for 45 seconds. Stir batter and microwave at 50 percent power for 45 seconds (batter will rise to just below rim of mug).
Press two chocolate pieces into center of each cake until chocolate is flush with top of cake. Microwave at 50 percent power for 30 to 60 seconds. Chocolate pieces should be melted and cake should be slightly wet around edges of mug and somewhat drier toward center. Let cakes sit for two minutes before serving.