For an even more intense flavor, you can use dark chocolate instead of milk chocolate.
7 tbsp butter
1 1/4 cups milk chocolate chips
2 tbsp sugar
1/4 cup confectioners' sugar
Spray 4 (3½-inch) ramekins with cooking spray. Preheat the oven to 350ºF. Place butter in a microwave-safe bowl and heat 1 min. Add the chocolate chips and stir until melted. Microwave an additional 30 sec. if needed, but do not overheat. Cool slightly.
Separate the eggs, reserving 2 of the egg whites for another purpose. Beat the 4 egg yolks with the sugar in a food processor for 5 min., or until the volume triples. Keeping the machine running, add the chocolate mixture. Turn processor off and gently fold in the beaten egg whites, a little at at time, until completely incorporated.
Divide the mixture between the ramekins and place in the baking dish. Fill the dish with enough boiling water to reach half way up the sides of the ramekins. Transfer baking pan with ramekins carefully to the oven. Bake 25 min., or until the top is set. Cool ramekins for 1 hour. Sprinkle the cakes with confectioners sugar.