Cooking Notes Vol. 071808

I've just read that for cake-like brownies you're to add one more egg than the regular recipe calls for.

Baking soda and baking powder are leavening agents. When mixed with acids (i.e. buttermilks, chocolate, honey, etc.) they cause the pastry to rise. In fact, the action starts to happen immediately while you're mixing the batter and so therefore it's important to bake promptly otherwise the dessert won't rise. Also, baking powder can be a substitute for baking soda (as in, if a recipe calls for both ingredients you can add a little more baking powder), however baking soda cannot be used to substitute baking powder.