Recipe by: 365 Great Chocolate Desserts. Preheat oven to 180ºC . Line a 23 cm square baking pan with foil. Grease foil. Prepare brownie mix according to package directions. Stir in coffee powder, 1 teaspoon rum extract, and one third 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 one third cup nuts, remaining half 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 0.75-to 3 cm slices. ----