* Speaking of “awesome”.
Adapted from Alice Medrich’s Bittersweet, this is one of the most popular brownie recipes on the internet and also this site. (The other is My Favorite Brownies. No, you don’t have to choose a side.) I refreshed this recipe in 2016 with new photos and in the process of taking them, couldn’t resist streamlining the recipe a little. Alice Medrich will never, ever steer you wrong in the kitchen but she could not get me to melt butter in a puddle of simmering water on a skillet (any way you prefer to gently melt butter works here too) or beat the batter “vigorously for 40 strokes with a wooden spoon or a rubber spatula.” The good news is that even if you’re stubborn, you will still have excellent brownies to eat an hour from now. Some people liken these to a boxed mix brownie, but way better. Depending on your feelings about box mixed brownies, this is a good or bad thing. We find them fudgy and dark; they never go to waste. Use the best cocoa you have; because it provides all of the chocolate flavor here, it counts.
Position a rack in the lower third of the oven and preheat the oven to 325°F. Line the bottom and sides of an 8×8-inch square baking pan with parchment paper or foil, leaving an overhang on two opposite sides.
Combine the butter, sugar, cocoa, and salt in a medium heatproof bowl and (Medrich’s method) set the bowl in a wide skillet of barely simmering water. Stir from time to time until the butter is melted and the mixture is smooth and hot enough that you want to remove your finger fairly quickly after dipping it in to test. Or (Deb’s method) you can melt the butter with the cocoa in a microwave too.
Both methods: Set the bowl aside briefly until the mixture is only warm, not hot. It looks fairly gritty at this point, but don’t fret — it smooths out once the eggs and flour are added.
Stir in the vanilla with a wooden spoon. Add the eggs one at a time, stirring vigorously after each one. When the batter looks thick, shiny, and well blended, add the flour and stir until you cannot see it any longer, then beat vigorously for 40 strokes with the wooden spoon or a rubber spatula. Stir in the nuts, if using. Spread evenly in the lined pan.
Bake until a toothpick plunged into the center emerges slightly moist with batter, 20 to 25 minutes is Medrich’s suggestion but it took me at least 10 minutes longer to get them set. Let cool completely on a rack. (I go further and throw mine in the fridge or freezer for a while; it’s the only way I can get them to cut with clean lines.)
Lift up the ends of the parchment or foil liner, and transfer the brownies to a cutting board. Cut into 16 or 25 squares.