Preheat the oven to 400 degrees F.

Using a small pastry brush, grease 5 (1/2-cup) individual ramekins with the softened butter, and sprinkle about 1 teaspoon sugar into each ramekin. Roll the sugar around the sides and bottom of each ramekin to coat completely, shaking out any excess sugar.

In a large metal bowl set over a pot of simmering water, melt the chocolate, stirring it with a whisk from time to time. Remove the melted chocolate from the heat.

In another bowl beat the egg whites with 1/4 cup of the sugar until stiff and glossy.

Whisk the egg yolks into the melted chocolate 1 at a time, add the Grand Marnier, and whisk in the remaining 2 tablespoons sugar. Fold in the egg whites until thoroughly blended. Pour the chocolate mixture into the prepared ramekins, filling each ramekin almost to the top with the batter. Place ramekins on a baking sheet and bake until they're puffed and somewhat firm, about 18 to 22 minutes.

To serve, place a ramekin on each of 5 plates and sift confectioners' sugar over the top of each souffle. Break the top of each souffle, and spoon in the warm Chocolate Grand Marnier Sauce, allowing it to drip over the sides. Serve immediately.