Instructions

• Preheat the oven to 325°F (163°C). Line baking sheets with parchment paper and place an oven rack in the center position.
• Place 2/3 cup of the dark chocolate chips in a microwave-safe bowl. Microwave on medium power for 30 seconds, stir, then continue to microwave in 15-second intervals, stirring after each, until the chips are just melted. Set the melted chocolate aside to cool slightly.
• In a medium bowl, sift or whisk together 1 cup flour, 1/4 cup unsweetened cocoa powder, 1 teaspoon baking soda, and 1/2 teaspoon salt; set aside.
• In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with an electric mixer, beat 1/2 cup softened unsalted butter, 1/2 cup packed light brown sugar, and 1/4 cup granulated sugar on medium-high speed until light and fluffy, about 3 minutes. Scrape down the bowl as needed.
• Add the melted chocolate to the butter mixture and mix until thoroughly combined.
• Add 1 large egg and 1 1/2 teaspoons vanilla extract; mix until well blended, about 1 minute.
• Add the dry flour-cocoa mixture and mix on low speed just until combined; do not overmix.
• Stir in the remaining 1 cup dark chocolate chips by hand until evenly distributed.
• Using a medium cookie scoop (about 1 1/2 tablespoons), drop rounded portions of dough onto the prepared baking sheets, spacing them about 2 inches apart.
• Bake for 12–14 minutes, until the tops have a cracked appearance and the edges are set. Cool the cookies on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.