1, Preheat oven to 325 degrees F. Line an 8″ square pan (I used a 9″, which resulted in slightly flatter brownies) with parchment paper so that there is an overhang on each side.

2, Let a skilletful of water come to a gentle simmer. In a heatproof bowl, place the butter, sugar, cocoa powder, and salt, and place it in the skillet. Stir while the butter melts. Once the mixture is hot, remove the bowl from the skillet and let it cool until it’s only warm. Using a wooden spoon, stir in the vanilla, then stir in the eggs, one a time, vigorously. Once the batter looks shiny and well-blended, stir in the flour until no streaks remain. Vigorously beat the batter for 40 strokes. Sti

3, Bake until a toothpick in the middle comes out slightly moist with batter, 20 to 25 minutes (in my 9″ pan, it took about 20 minutes). Remove and let cool completely before lifting out of the pan and transferring to a cutting surface. Cut to your desired size