I've been putting this together in my head for about a decade, and I'm finally ready to take a stab at it.
People take brownies for granted a lot, especially given how many mixes are out there.
Certainly, the myth that brownies are simply a cake with the wrong leavening is a lie that needs to be eliminated post haste.
Brownies that are like cake aren't brownies, they're a bad cake. Real brownies should be dense and fudgey, they should be sticky and gooey, and they should go great heated up with ice cream or whipped cream. There's a density, an intensity, required by them.
In fact, the very belief that there should be leavening in brownies is a misnomer. This may be regarded as an opinion, but it's the right one.
If you were to graph brownies across three axis, there would be three intersecting qualities which really define the brownie. They are as follows:
Real custard, at its heart, is a mixture of sugar/syrup and eggs, brought together in a slurry and then baked for a reasonable time until they set.
Ganache is a blend of chocolate and butter or cream.
When you bring custard and ganache together, you get a sort of pudding or mousse, depending on the quantities you've brought together.
When you incoprorate flour, whether wheat, rice, or other, you are essentially introducing a factor which can bring air into the equation, sort of a lattice work which brings size and airiness to the overall result.
Lisa Yokelson's "Essence of Chocolate" brownies, which I've used as my "go-to" base for about a decade now (see Cream Cheese Brownies) is a stick and a half of butter and four ounces of unsweetened chocolate, and then a cup and a half of flour with nearly three tablespoons of cocoa incorporated, as well as four eggs and 2 cups of sugar, preferably vanilla infused.
These brownies are a dense, flavorful, but relatively dry offering. It's much more like the legendary unrisen cake, and makes a great base for other deserts, or something to use as a combo to mix with chips or flavoring. It's a pallette in and of itself, rather than the main dish.
On the other hand, Elisabeth Prueitt's base brownies from the Tartine bakery book make chocolate the main affair. With a full pound of chocolate to the stick and a half of butter, the chocolate completely takes over the picture. Additionally, it ups to 5 eggs, pushing the limits of what custard can be in this dish. For best results, the brownies literally have to be allowed to sit for a day, much like fine ganache, so that the flavor can really develop, at which point the full texture and flavor of the gooey, fudgey brownies as a canvas for the brownies really come through. There's no point in putting other things into this sort of brownie...the texture and flavor as they are are precisely the point.
So we have to ask, not only what it's worth to us to have good brownies, but precisely what are we trying to accomplish? Is this just some easy fallen cake dish with cocoa powder that we're making because there's nothing left in the cupboard and we need something sweet on a friday night? Are we trying to make something truly overwhelming, fudgy, and dark which will blow our minds and drive us to further heights and depths of exploration?
I certainly know what I'm exploring.
3/4 C unsalted butter
1 lb. bittersweet chocolate, chopped (It's easier to just buy a bag or two of chips, honestly.)
3/4C + 2Tbsp AP flour
5 large eggs
2 Cups light brown sugar
Preheat oven the oven to 350. Butter a 9x13 glass baking dish.
Get a saucepan and melt the butter in it. Remove it from the heat, and add the pound of chocolate (I usually just use chocolate chips, as it's less work. Nestle has some nice 53% chips right now, though Ghiradelli is of course always superb with their 65% bittersweet. Stir, it usually all melts together pretty quickly.
Sift the flour into a small mixing bowl.
In a mixing bowl, combine the eggs, sugar, salt and vanilla. Using a mixer fitted with the whisk, beat on high until the mixture thickens and becomes pale in color. Using a rubber spatula, fold in cooled chocolate. Add the flour and fold it in quickly, but gently with the spatula so that you don't deflate the air. (this doesn't always entirely work out, and, really, they're just fine dense, they just don't bake the same way, and you'll probably have to bake them longer. Also: I succumbed to the temptation to use dark brown sugar instead of light brown. I do not suggest this, it's insanely intense. The light brown is good enough.)
Pour the batter into the prepared dish and smooth the top. If you're using nuts, evenly distribute them across the batter. Bake until the top looks slightly cracked and feels soft to the touch. about 25 minutes. (or closer to 40 if there isn't much air in them) Let cool completely.
A word about this brownie: It's quite gooey, and it really, really improves in flavor if you let it sit for a day or two before eating.