What is the name of this French cake?

I love this pastry. I discovered it while studying in Angers, France with my wife. There are so many pastries that it is sort of a guessing game. After discovering the opera, I never got anything else from the shop. I thought, "Nothing can top this!". However, not all "pâtisseries" bake them. Alas. They are difficult to find in the US too.