The macaron is commonly filled with ganache, buttercream or jam filling sandwiched between two cookies.
The name is derived from the Italian word macarone, maccarone or maccherone, the Italian meringue.
In a Slate article on the topic, Stanford Professor of Food Cultures Dan Jurafsky indicates that "macaron" (also, "macaron parisien", or "le macaron Gerbet") is the correct spelling for the confection.