As y'all probably guessed by the title I did not make Baby Cakes, I didn't feel like messing around with my four inch pans and decided to make a 12 inch cake alternative instead. And why yes I do have a 12 inch spring form cake pan, I'm hard core.
The resultant cake was delicious. There is nothing like fresh rhubarb and loved the flavor it imparted. I couldn't find crème fraîche nor did I feel like making it so I used the third alternative listed in the recipe, sour cream. It worked out very well, though I would like to try making the cake sometime with crème fraîche. Also I think it was easier to make it in one pan than 8 (!) mini cake pans, it would be tricky dividing the caramel between all those pans.
Oh and my one modification, I lined the cake pan so I wouldn't mess up the rhubarb when I turned out the cake. It was very easy to peel off after I removed the spring form pan from the overturned cake.
This would make an excellent brunch or tea-time treat. Next time, and there will be a next time, I might just halve the recipe for a more manageable quantity of cake.