In a clean, dry bowl, beat the egg whites on medium-high speed until they hold a stiff peak. Gently fold together the egg whites with the chocolate mixture, until just combined. Divide the batter evenly among the 6 ramekins. Arrange the ramekins on the rimmed baking sheet and place into the oven. Bake the cakes for 12-15 minutes. The cakes will rise and be dry around the edges when they are done. Remove the sheet tray of ramekins from the oven and run a knife around the edge of each ramekin to release the cake. Carefully invert them on a plate, remove the parchment paper rounds and sprinkle with confectioners’ sugar. Serve hot!