I certainly cannot call myself an expert on brownies, which are very much an American sweet. They seem to come in all varieties, from fudgy and chewy to cakelike, and from tiny cookie-sized pieces to big squares. It is up to you how to portion the baked sheet. These brownies hold together well if you cut them small.
I happen to like raisins, so in the second edition of this book I added 6 ounces