Types of Brownies
The classic brownie consists of just a few ingredients: butter, sugar, chocolate, eggs, and flour.
Fudge type brownies have a minimum of flour--about half a cup--and no leavening such as baking powder. Melting the butter rather than creaming it with sugar yields a denser, fudgier outcome. Unsweetened chocolate is the standard, with a full cup of sugar required to balance its bitterness. Either granulated or brown sugar may be used. Substitute one for the other in equal proportions. The deeper the color of the sugar, though, the more pronounced the molasses flavor.
Cake type brownies contain less butter and more flour than fudge type brownies, as well as a bit of baking powder to make them softer and lighter. Often the softened butter is creamed with the sugar rather than melted with the chocolate, which incorporates air into the mixture causing the brownies to rise higher. Many cakelike recipes also call for a bit of milk to add tenderness.
Chewy type brownies usually get their texture from extra eggs and a combination of different types of chocolate. Of all the chocolate types, unsweetened chocolate has the highest proportion of starches, which create a stiffer-textured brownie. Semi-sweet chocolate produces a creamier texture. Put the two together, often with a few tablespoons of cocoa powder to round out the flavor and thicken the texture, and you get a rich, satisfyingly chewy result.
Blondies are really butterscotch bars, made with brown sugar, butter, and eggs and usually nuts, but no chocolate. Generally, blondies have a cakelike texture.