The Best Brownies
If you want to double this recipe and use a 9x13-inch baking dish, that will also work, although I believe they'll be a little bit thicker and take a little bit longer to bake. Buttered foil will also work instead of parchment paper.
You can use 1/4 teaspoon plus 1/8 teaspoon fine salt instead of kosher.
Make sure you use chocolate that is 99 to 100% pure cacao.