Preheat the oven to 160°C (140°C fan forced). Grease and line a 20cm square cake tin with baking paper. Make, bake and cool the cake mix as directed on the box.
Trim the rounded tops off the cake (if necessary) and brush off any crumbs. Place cake, cut-side up, on a cake board. Spread with a quarter of the vanilla icing. Chill for 30 minutes, then spread the remaining icing onto the top and sides of the cake leaving a smooth surface. Chill for a further 30 minutes.
On a surface lightly dusted with icing sugar, roll out the red icing to a large 2-3mm thick rectangle. Cut 2 x 2.5cm wide strips from the longest length and place onto the cake, crossing in the middle, for the ribbon. Trim the edges neatly at the base of the cake.
Cut 2 x 24cm long and 2.5cm wide strips from the icing. Using one strip, fold in each end from the outside to the middle to make a bow. Press in the middle to seal and tuck a little kitchen roll or a wooden spoon handle into the loop to keep the shape. Cut a 6cm x 2.5cm piece of icing and wrap around the middle of the bow. Press gently to seal. Cut the second 24cm length of icing in half and cut an inverted V into one end of each. Place onto the cake with the straight end pressed onto the middle of the cake, where the 2 other ribbons cross over.
Place the bow on top and press gently to stick. Set the chocolate beans into the vanilla icing around the cake to decorate. Remove the kitchen roll or wooden spoons from the bow once ready to serve.