A brownie is a square baked dessert. It is a cross between a cake and a soft cookie in texture and comes in a variety of forms. They can be made without anything aside from the essential ingredients, but nuts (usually walnuts) and chocolate chips are commonly added to make them more substantial. Another variation made with brown sugar and chocolate bits but without melted chocolate in the batter is called a blonde brownie or blondie. The brownie was developed in the United States at the end of the 19th century and popularized in the U.S. and Canada during the first half of the 20th century.