As author Rose Levy Beranbaum explains, "Hamantaschen are the cookies traditionally made for the Jewish holiday Purim. They're triangle shaped to represent the hat worn by the villain Haman in the Purim story." They were originally made with a yeast-based dough, but over time, with the availability of baking powder, have become more of a cookie. Poppy seed filling is the most common, however, fillings made with dates, as well as apricot jam or raspberry jam are popular. You may even find them with chocolate, Nutella, or even savory fillings.