Instructions

• Preheat the oven to 350°F. Line a large baking sheet with a Silpat or parchment paper and set aside.
• In a large bowl, whisk together 2 1/4 cups all-purpose flour, 1/2 cup unsweetened cocoa powder, 1 teaspoon baking soda, 1 teaspoon cream of tartar, 1 teaspoon ground cinnamon, and 1/2 teaspoon sea salt. Set the dry mixture aside.
• In the bowl of a stand mixer (or a large mixing bowl with a hand mixer), beat 1 cup unsalted butter (room temperature) for about 30 seconds until smooth.
• Add 1 cup packed brown sugar and 1/2 cup granulated sugar to the butter. Beat for about 2 minutes, until the mixture is light and fluffy, stopping once to scrape down the sides of the bowl.
• Add 2 large eggs and 1 teaspoon vanilla extract. Mix just until combined.
• Add the dry ingredient mixture to the wet ingredients and mix on low speed (or fold by hand) until just combined and no large streaks of flour remain. Do not overmix.
• In a small bowl, combine 1/4 cup granulated sugar and 1 1/2 teaspoons ground cinnamon. Stir until evenly mixed—this is the rolling mixture.
• Use a cookie scoop or tablespoon to portion dough into balls of about 2 tablespoons each.
• Roll each dough ball in the cinnamon-sugar mixture until evenly coated. Place the coated dough balls on the prepared baking sheet about 2 inches apart.
• Bake in the preheated oven for 8–10 minutes, until the cookies are set around the edges but still soft in the centers. Avoid overbaking.
• Let the cookies cool on the baking sheet for about 5 minutes, then transfer them to a cooling rack to cool completely.