Chocolate Grand Marnier Souffles with Black Walnut Caramel Sauce

Name: Chocolate Grand Marnier Souffles with Black Walnut Caramel Sauce
Ingredients: Melted butter, for brushing ramekins; Sugar, for coating ramekins; 8 ounces semisweet chocolate, chopped into small pieces; 3 ounces butter; 7 eggs, separated; 1/4 cup orange liqueur (recommended: Grand Marnier); 1/2 teaspoon vanilla extract; 1/2 teaspoon cream of tartar; 1/2 cup sugar; Confectioners' sugar, for garnish; Black Walnut Caramel Sauce, recipe follows; 1 1/4 cups sugar; 1/3 cup hot water; 1 cup chopped black walnuts; 1/2 cup heavy cream; 2 teaspoon vanilla extract; 4 ounces whole unsalted butter