Preheat oven to 375 degrees F.
Brush the inside of 6 (10-ounce) ramekins with melted butter. Put a few tablespoons of sugar in a ramekin, and roll to coat the inside with sugar. Pour the sugar in the next ramekin and continue to coat the remaining ramekins in the same manner, adding more sugar, if necessary.
Melt the chocolate and butter over a double boiler, stirring until smooth. Set aside to cool the mixture until it is just warm to the touch.
In an electric mixer with the whisk attachment, beat the egg yolks until light and foamy. Mix in the liqueur and vanilla. Fold in the chocolate mixture.
In a clean mixer bowl, beat the egg whites and cream of tartar to soft peaks. With the mixer running, add the sugar and beat to stiff peaks.
In 3 additions, fold the whites into the chocolate mixture until just combined. Fill the ramekins with the mixture. Bake until the souffles have risen and the tops and edges are lightly browned. Remove from the oven and immediately sift confectioners' sugar over the tops. Place on a plate and serve immediately. At the table, poke a hole in the center of the souffle with a spoon and pour in Black Walnut Caramel Sauce.
In a saucepan, combine the sugar and water. Bring to a boil, cook until the caramel is beginning to turn brown. Carefully swirl the pan until the caramel turns a deep brown.
Immediately add the walnuts and cream, being careful not to let the cream boil over.
Reduce the heat to a simmer. With a wooden spoon, scrape the bottom of the pan until all caramel is dissolved and sauce is smooth. Remove from the heat. Add vanilla and butter. Stir until the butter is completely dissolved.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Brian Lewis, The Fairmont, Kansas City, MO