I love baking special 3D cakes for the kids, but both birthdays are over in March and thus the fun. I thought I would do something special for my husband's birthday this year. He likes Star Wars, so I went with an R2D2 birthday cake. I didn't want too much cake and decided to go with a smaller pan (smaller diameter means less height and cake mix).
I used a 6 inch Wilton cake pan. I made two cake mixes (4 total layers). I had previously cut two pieces of cardboard just smaller than my pan size and covered them in clear plastic wrap to put under each main section of the cake. For the first section, I leveled the layers and used the tallest two as the base of the cylinder. I placed three skewers down this section to keep it from shifting during transport. The remaining was leveled and used as the head. I rounded the top with a knife to make a semi-circle (dome). A small tip: R2D2 is approximately 2/3 cylinder and 1/3 semi-circle, when proportioning your cake sections.
I used the Wilton Butter cream Icing recipe to cover the cake. I first coated both sections in white and allowed them to dry. Then I smoothed them out lightly with a paper towel. Then I covered the head in a light gray colored icing and the cylinder in one more coat of white. I smoothed and then placed the head on top of the cylinder. From there I started piping on the appropriate colors and smoothing as necessary.
The armatures are made of rice krispie treats covered in icing (difficult, but possible with a thick enough layer and persistence). I used one batch of treats and used a knife to cut out my thoughts on the appropriate shape of armatures. I attached them with skewers on the top and bottom and covered the holes with icing details. The raised lens is made with the bottom of an ice cream cone dipped in dark chocolate
My husband loved this cake. He even had me add his age on the back in binary! The cardboard under the head section made it easy to slice the cake at the party as well. Everyone loved this cake!