I wasn't familiar with the term, but Wiktionary has some good hints: n. A small gateau or sponge cake, often shaped like an elongated scallop shell. n. Someth

I wasn't familiar with the term, but Wiktionary has some good hints: n. A small gateau or sponge cake, often shaped like an elongated scallop shell. n. Something which brings back a memory; a source of nostalgia or evocative memories (used with reference to its function in Marcel Proust's In Search of Lost Time).