I did this simple R2D2 cake by first making two 8X11 sheets. I used one for the body and the other one for the head and arms. Before cutting them I had previously measured and cut the right proportions for everything. I highly recommend doing that! Also make sure you freeze your cake before cutting.
Next I used cream cheese frosting and crumb coated the cake and put it in the fridge for a bit. I covered the rest of the cake and just used food coloring on the rest. The black may look kind of off because I bought it in a tube and put it directly on the cake. I would recommend getting some gel food coloring and I guarantee you’ll have an awesome black color without the price of the tube. It only took maybe an hour and some to decorate it, and it turned out pretty well if I do say so myself.