Smetannik is a Russian cake with sour cream frosting; many thin layers can raise the ratio of frosting to cake considerably. (This is good.) Some of the larger markets in South Brooklyn feature a half-dozen flavors; this smaller shop offered less variety, but I was more than happy to find hazelnut.
Z Fancy Foodz
1212 Ave. Z (East 12th St.-Homecrest Ave.), Sheepshead Bay, Brooklyn
347-492-3315