A brownie is a flat, baked square or bar made from chocolate or cocoa powder. The brownie is a cross between a cake and a cookie in texture. Brownies come in a variety of forms. They are either fudgy or cakey, depending on their density, and they may include nuts, frosting, whipped cream, chocolate chips, or other ingredients. Brownies are developed in the United States and popular in both the U.S. and Canada.