- 1 1/2 cups all-purpose flour
- 2 teaspoons ground cinnamon
- 1 teaspoon baking powder
- 1 teaspoon espresso powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon kosher salt
- 2 large eggs
- 1 teaspoon vanilla extract
- 10 tablespoons unsalted butter, room temperature
- 3/4 cup granulated sugar
- 3/4 cup (packed) light brown sugar
- 8 ounces high-quality milk chocolate, chopped
- A heavy (preferably cast-iron) 12-inch skillet
- Preheat oven to 375°F. Whisk flour, cinnamon, baking powder, espresso powder, baking soda, and salt in a medium bowl. Lightly beat eggs and vanilla in a small bowl.
- Using an electric mixer on medium speed, beat butter, granulated sugar, and brown sugar in a large bowl until light and fluffy, 3–4 minutes. Add egg mixture and beat, occasionally scraping down sides of bowl, until mixture is pale and fluffy, 3–4 minutes. Reduce mixer speed to low and gradually add dry ingredients, beating until just incorporated. Fold in chocolate with a spatula.
- Press dough evenly into 12″ skillet. Bake cookie until golden brown around the edges and center is still soft, 20–25 minutes. Let cookie cool in skillet before slicing.
- Cookie can be made 3 days ahead; cover and store at room temperature.