Preheat the oven to 350 degrees. Line a 15 1/2 by 10 1/2-inch jelly pan with aluminum foil. Let the foil come over the sides of the pan, about 2 inches. Butter the foil. Stir the chocolate, butter and Kahlua together. Sift the flour and cocoa together. Using an electric mixer with a whip attachment, beat the eggs at high speed until the eggs are frothy. While beating the eggs, slowly add the sugar. Beat the eggs and sugar for 8 to 10 minutes or until the mixture is pale yellow in color and forms a ribbon-like texture. Beat in the chocolate mixture. Fold in the sifted flour cocoa mixture into the egg mixture in two batches. Fold in the nuts, espresso powder, and chips. Pour into the prepared pan and bake for 20 to 25 minutes or until the center of the cake is done. Do not overbake. Let the brownies cool. Using a 4 inch round cutter, cut the brownies into 8 circles. Place one brownie circle in the center of the plate. Place a scoop of ice cream on the brownie. Top with a second circle. Drizzle with the chocolate sauce. Garnish with whipped cream, espresso beans, espresso powder, powdered sugar, and mint.