04Place the egg whites in a large bowl with the cream of tartar. Using a hand mixer, whip the egg whites until soft peaks. Gradually add in the 1/4 cup sugar and continue whipping until firm peaks. Fold the egg whites into the warm chocolate mixture.05Place a ball of the chilled chocolate mixture in each of the ramekins. Spoon the souffle mixture over the chocolate balls and up to the rim of the ramekins. (At this point the souffle can be covered and kept refrigerated for 2 days.)06Place the ramekins in a hot water bath and bake until golden on top and the souffle has risen, about 30 minutes (40 minutes if refrigerated). Remove from the oven and serve immediately.