According to this argument, matzo and its derivatives are neither leavened nor leavenable and therefore are permissible for consumption during Passover.
en.wikipedia.org These festivals are observed on the day after Passover, when eating of ordinary food (chametz) resumes.
en.wikipedia.org Typical Passover sponge flavorings include pecans, almonds, lemon, poppyseeds, apples, and dark chocolate.
en.wikipedia.org Typically, Passover sponges are made with matzo meal, matzo flour, or potato flour, since raw wheat products may not be used.
en.wikipedia.org They celebrate it once per year, noting that it was instituted on the Passover, an annual festival.
en.wikipedia.org