R2D2 is one of the most famous robots of all time, the bleeping maintenance 'droid with attitude, also known as Luke Skywalker's sidekick in the original "Star Wars" film series. For "Star Wars" fans, big and small, an R2D2 cake would make any occasion special. Making an R2D2 cake requires a bit of patience, but if you can find your way with a piping bag, it shouldn't be too difficult.
Place a large sheet cake onto a foil-lined cake board and freeze it overnight. While freezing, draw the outline of R2D2 on a piece of paper, using the reference picture as a guide; make the outline as large as you want the finished cake to be. Cut out the outline with scissors.
Remove the cake from the freezer in the morning then place the cut-out outline of R2D2 on top of the cake and carefully cut around the outline with a sharp knife held vertically to create straight sides.
Cover the R2D2 cake shape in a 1/8-inch-thick layer of white icing smoothed over with a spatula then pop it back in the freezer. If you don't want to freeze it overnight again, leave it for three to five hours, or until the icing is very hard.
Remove the cake from the freezer and use the tip of the knife to score the colour blocks of the R2D2 'droid onto the white icing, using the reference photo as a guide.
Attach a medium, round piping nozzle to a piping bag and half fill it with dark blue icing. Twist the top of the piping bag and hold it with your preferred hand, with the other hand as a guide near the tip of the piping bag.
Pipe on the outline of the different colour blocks on the R2D2 'droid, as well as an outline all around the perimeter of the cake.
Attach a medium star nozzle to a piping bag and half fill it with white icing. Fill in the white blocks by piping star dots in rows inside the outlined blocks. Do the same with the light blue colour blocks.
Attach a medium, round nozzle to a piping bag and half fill it with red icing. Pipe on red circles on the R2D2 head, in the position depicted in the reference picture. Leave the cake to fully defrost in a cool place before consuming.
Simplify the R2D2 shape if the original shape is too complex -- a rectangle body, with a semicircle head on top will convey R2D2 to even the most unenthusiastic "Star Wars" aficionado. R2D2's head is actually silver, however silver icing is hard to come by and grey is unappealing on a cake, so white is substituted. If you want to be true to the original colours, use grey icing on the head.