That question from reader Phil H., and it’s good one. The thing is, in most of the English-speaking world, the term “petit four” refers to a very specific thing. That being a small, layered cake covered with poured fondant. Among the French, however, the term refers to an entire family of small sweets. The word “petit four” is thus used in the same way we might use the term “appetizer.”
In France, petits fours come in two types, “iced” (petits fours glacés) and “dry” (petits fours secs). The little cakes we know as petits fours fall into the former category, and macaroons — along with cookies and small, laminated pastries — fall into the latter.