Ingredients

  • 13 cup granulated sugar (about 2 1/2 ounces plus 1/2 cup for coating)
  • 1 12 cups unbleached all-purpose flour (7 1/2 ounces)
  • 34 cup Dutch-processed cocoa powder
  • 12 teaspoon baking soda
  • 14 teaspoon table salt (plus 1/8 teaspoon table salt)
  • 12 cup dark corn syrup (see note)
  • 1 large egg white
  • 1 teaspoon vanilla extract
  • 12 tablespoons unsalted butter (1 1/2 sticks softened 70 degrees)
  • 13 cup dark brown sugar (about 2 1/2 ounces packed see note)
  • 4 ounces bittersweet chocolate (chopped into 1/2-inch pieces see note)

Method

  • Adjust oven racks to upper- and lower-middle positions and heat oven to 375 degrees.
  • Line 2 large (18- by 12-inch) baking sheets with parchment paper.
  • Place 1/2 cup granulated sugar in shallow baking dish or pie plate.
  • Whisk flour, cocoa powder, baking soda, and salt together in medium bowl.
  • Whisk corn syrup, egg white, and vanilla together in small bowl.
  • In stand mixer fitted with paddle attachment, beat butter, brown sugar, and remaining 1/3 cup granulated sugar at medium-high speed until light and fluffy, about 2 minutes.
  • Reduce speed to medium-low, add corn syrup mixture, and beat until fully incorporated, about 20 seconds, scraping bowl once with rubber spatula.
  • With mixer running at low speed, add flour mixture and chopped chocolate; mix until just incorporated, about 30 seconds, scraping bowl once.
  • Give dough final stir with rubber spatula to ensure that no pockets of flour remain at bottom.
  • Chill dough 30 minutes to firm slightly (do not chill longer than 30 minutes).
  • Divide dough into 16 equal portions; roll between hands into balls about 11/2 inches in diameter.
  • Working in batches, drop 8 dough balls.
  • into baking dish with sugar and toss to coat.
  • Set dough balls on prepared baking sheet, spacing about 2 inches apart; repeat with second batch of 8.
  • Bake, reversing position of the baking sheets halfway through baking (from top to bottom and front to back), until cookies are puffed and cracked and edges have begun to set but centers are still soft (cookies will look raw between cracks and seem underdone), 10 to 11 minutes.
  • Do not over bake.
  • Cool cookies on baking sheet 5 minutes, then use wide metal spatula to transfer cookies to wire rack; cool cookies to room temperature.
  • When the cookies have cracked but still look wet between the fissures, take them out of the oven.
  • This ensures a moist, chewy texture.
  • Note:TOO SMALL Tiny chocolate pieces will melt and disappear into the dough when baked.
  • JUST RIGHT Half-inch chunks contribute chocolate flavor while staying intact.
  • RECIPE TESTING ELIMINATE THE YOLK Reducing the egg to a single white cuts down on excess fat, which can make cookies too tender.
  • INCORPORATE COCOA Using cocoa powder instead of melted chocolate in the batter keeps tenderness in check.USE LESS WHITE SUGAR Replacing some white sugar with dark corn syrup and dark brown sugar boosts chewiness.