Whole-Wheat Chocolate Chip Cookie Bars

Ingredients

• 2¼ cups (9 oz/270 g) whole-wheat flour, spooned and leveled
• 1 tablespoon instant espresso powder
• 1½ teaspoons kosher salt, or ¾ teaspoon fine sea salt
• 1 teaspoon baking soda
• 1¼ cups (9 oz/250 g) packed light brown sugar
• ½ cup (3½ oz/100 g) granulated sugar
• 1 cup (2 sticks) unsalted butter, melted and cooled to room temperature
• 2 large eggs
• 2 teaspoons pure vanilla extract
• 12 ounces (340 g) chopped bittersweet chocolate, or 2 cups (345 g) bittersweet chocolate chips

Instructions

1. Preheat the oven to 350°F (175°C) with a rack in the center. Butter a 9-by-13-inch (20-by-30-cm) baking dish and line it with parchment, leaving a 2-inch (5-cm) flap overhanging on two sides.
2. Whisk the flour, espresso powder, salt, and baking soda in a medium bowl. In a large bowl, whisk both sugars, breaking up any lumps. Add the melted butter and whisk vigorously for about 1 minute, until the mixture forms one mass. Scrape down the bowl.
3. Whisk one egg into the sugar-butter mixture until fully incorporated. Whisk in the second egg and vanilla. Add the dry ingredients and stir with a spatula until no dry streaks remain, then fold in the chopped chocolate or chocolate chips.
4. Scrape the dough into the prepared pan and smooth it into an even layer. Refrigerate for at least 10 minutes while the oven preheats.
5. Bake, rotating halfway through, for 25 to 30 minutes, until golden brown and the crust looks matte rather than wet or glossy. Cool completely before cutting into 24 bars.