First of all, give yourself at least three days to do this. Do not attempt this the day before the party. It will end badly.
Day one. Bake your cake and freeze it.
Day 2, we get the large enough cake to cut the shape of R2D2 out of the freezer. There is a Wilton pan, from the 1980's that can be found for a mere fortune on Ebay, if one is inclined. However it can be done without it just fine.
This cake should be frozen as solid as you can possibly get it.
Make a paper shape like this one. I can't stress enough to not freehand this, unless you are super amazing talented and can create a perfectly mirror imaged R2.
I am not super amazing talented and the thought of cutting this out without a pattern makes my chest tight with stress. Just sayin'.
Using a very sharp knife, cut out your R2D2 using the pattern.
We are still on Day 2.
Do a crumb coating on it and any other shapes you want. The chocolate cake was SO large and SO yummy that I used part of it to write on and there is some still for a trifle! I can't wait!
Time to put it back in the freezer. Trust me. Doesn't affect the taste at all, I have people waiting impatiently for this recipe and perhaps the freezing of it made it even moister in the end.
I also actually enjoyed making this cake, I promised myself I would take time, do it step by step and slowly without stress. It actually worked!
If you wanted, you could move on to the next step after this, BUT the tracing is easier with frozen icing.
Looking at the main R2D2 picture in this point, take a knife and trace out the “blocks” that you will fill in with color.
Because the icing is frozen you can trace, then correct by smoothing it out, then try again.
You can see how it's done block by block, color by color. Getting the basic blocks is hard but if you have something to follow it's actually a piece of cake!
Har de har har.
And this is how I learned, I haven't ever taken any classes, just practiced on wax paper while my mom decorated cakes.
So cute and little and drawing a bear cave. My icing Picasso. She had so much fun.
And the finished product! I put it back into the freezer for another evening and pulled it out the next morning to completely defrost.