Chewy Brownies

"**In the video, Julia mistakenly calls for 1 1/2 cups of oil. The correct amount should be 1/2 cup of oil.** Brownies are a tricky business: Homemade recipes have better flavor, while boxed mixes claim best texture. Our goal was clear: a homemade brownie with chewiness (and a shiny, crisp, crackly top) to rival the boxed-mix standard—but flush with a rich, deep, all-natural chocolate flavor. To start, we consulted our science editor to see if he knew of any tricks that boxed brownies use to achieve their chewy texture. He explained that boxed brownie mixes derive their chewy texture from the right combination of saturated (solid) and unsaturated (liquid) fats. Boxed brownie mixes already come with the saturated fat component, so when a cook adds unsaturated vegetable oil, the liquid fat and powdered solid fat combine in a ratio designed to deliver maximum chew. To get the same chew at home, we tested and tested until we finally homed in on the ratio that produced the chewiest brownie. To combat greasiness, we replaced some of the oil with egg yolks, whose emulsifiers prevent fat from separating and leaking out during baking. We focused on flavor next. Because unsweetened chocolate contains a similar ratio of saturated and unsaturated fat to butter, we could replace some of the butter with unsweetened chocolate, thereby providing more chocolate flavor. Espresso powder improved the chocolate taste as well. And finally, folding in bittersweet chocolate chunks just before baking gave our chewy, fudgy brownies gooey pockets of melted chocolate and rounded out their complex chocolate flavor...."