Recipe by: 365 Great Chocolate Desserts. Preheat oven to 350 degrees F. Line a 9-inch square baking pan with foil. Grease foil. Prepare brownie mix according to package directions. Stir in coffee powder, 1 teaspoon rum extract, and 1/3 cup nuts. Turn batter into prepared baking pan. Bake according to package directions, 25-28 minutes, being careful not to overbake. Let cool completely. To prepare rocky road filling and topping: In a medium bowl, with an electric mixer on medium speed beat cream to soft peaks. Beat in cocoa, powdered sugar, and salt until well mixed. Fold in remaining 1/3 cup nuts, remaining 1/2 teaspoon rum extract, and marshmallows. o assemble cake, cut brownie square into 3 equal strips. Stack strips together with rocky road filling in between and on top. Refrigerate 4 to 5 hours or overnight to allow flavors to meld. To serve, cut into 3/4-to 1-inch slices. ----