I received this email from BakeSpace.com and thought this was interesting info re brownies:
Rosemary
What Makes A Brownie A Brownie?
The classic brownie recipe consists of just a few ingredients: butter, sugar, chocolate, eggs, and flour. But there are lots of variations, such as:
FUDGY BROWNIES are made with less flour and no leavening (e.g., baking powder). Melting the butter rather than creaming it with sugar yields denser, fudgier brownies.
CAKE-LIKE BROWNIES contain less butter and more flour than fudgy 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. Many cake-like recipes call for a splash of milk, which also gives brownies a light texture.
CHEWY BROWNIES usually get their texture by modifying two ingredients: an extra egg (or two) and a combination of different types of chocolate, such as unsweetened and semisweet. 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 as well), but no chocolate. Typically, blondies have a cake-like texture.