It's high time I set the record straight: macaron is not an alternate spelling of macaroon! In fact, the two terms refer to distinctly different things. Both macarons and macaroons are confections, and both names are derived from ammaccare, which is Italian for "to crush" — but that's where the similarities end.
A macaron specifically refers to a meringue-based cookie made with almond flour, egg whites, and granulated and powdered sugar, then filled with buttercream or fruit spread. The delicate treat has a crunchy exterior, and a weightless interior with a soft ending that's almost nougatlike in its chewiness. To add to the confusion, it's often called a French macaroon.
In contrast, the word macaroon is a generic phrase that is applied to a number of small, sweet confections. Mostly, the term is equated with the the moist and dense coconut macaroon, which is composed of egg whites, sugar, and dried coconut, piped with a star-shaped tip, and often dipped in chocolate. The coconut macaroon, or congolais, as it's known in France, is frequently served during Passover because it contains no flour. Which would you rather eat?