I tried making petite fourer. The recipe goes along the lines of this: make two sponge cakes. Cut them in half into two layers and spread jam on one side, then put the other layer on top. Cut again so each spong cakes consists of two thinner long cakes. Cut them up in rhomb shapes. Make frosting from insane amounts of frosting sugar. DIP THE RHOMBS IN THE FROSTING. Add sprinkles. Done. The only problem is that the frosting is like thick glue and the rhombs fall apart when I try to dip them. Apart from that you’re pretty much drowning them in liquid sugar. They were pretty good but the frosting measurements definitely needs some tweaking.