1 1/4 cups all-purpose flour
1/4 cup plus 2 tablespoons unsweetened cocoa powder
1 teaspoon cornstarch
3/4 teaspoon baking soda
1/2 teaspoon salt
1/2 cup (1 stick) unsalted butter, at room temperature
1/2 cup packed light brown sugar
1/4 cup granulated sugar
1 large egg, at room temperature
1 teaspoon vanilla extract
1 cup M&Ms
Preheat oven to 350 F. Line two baking sheets with parchment paper.
In a medium bowl, sift the flour, cocoa powder, cornstarch, baking soda, and salt togetherIn the bowl of a stand mixer fitted with the paddle attachment, cream the butter and both sugars on medium speed until light and fluffy, about 3 minutes. Beat in the egg and then the vanilla. With the mixer on low, gradually add the dry ingredients, beating just until combined.
Using a small cookie scoop (mine measures about 1 1/2 inches across), portion the batter onto the prepared baking sheets, spacing the cookies about 2 inches apart and press and M&M onto the dough. Bake for about 8 minutes.
Transfer the baking sheets to wire racks and let the cookies cool for a few minutes then remove the cookies to the wire rack to cool completely. Repeat with the rest of the dough.
**Note this does not make a big batch of cookies. If you look at the measurements and compare it to a typical chocolate chip cookie dough for instance, you will notice that it is approx half of that. Just a little heads up.