That cake is adorable! Looking at it I am thinking they probably used a 10" pan but you totally could do it in a 14". Just make your eyes and everything to scale so it all works. Might be helpful to use your pan and cut a paper pattern that is 14" round and then make your eye circles on the computer and size them to fit and use them for patterns. Can't wait to see your finished project. It is going to be so cute!