A nice thing happened on the way to figuring out this cookie version of the popular graham cracker, milk chocolate, and marshmallow s’mores combination. During baking, many of the marshmallows in the graham cracker crumb batter melt, the sugar in the marshmallows caramelizes, and the result is cookies with crisp bits of caramelized sugar throughout. You don’t have to do anything to make it happen—baking does it automatically.
makes 15 cookies • cookie making 20 minutes • cookie baking 325 degrees, two baking sheets for about 15 minutes each
¾ cup (1½ sticks) unsalted butter, at room temperature
½ cup sugar
1 large egg
1 teaspoon vanilla extract
3 cups graham cracker crumbs
¼ cup unbleached all-purpose flour
¼ teaspoon salt
1½ cups (about 8½ ounces) milk chocolate chips
1½ cups miniature marshmallows
Position a rack in the middle of the oven. Preheat the oven to 325 degrees F. Line two baking sheets with parchment paper.
MAKE THE COOKIES. In a large bowl, using an electric mixer on medium speed, beat the butter and sugar until smoothly blended, about 1 minute. Stop the mixer and scrape the sides of the bowl as needed during mixing. Add the egg and vanilla, mixing until blended, about 1 minute. On low speed, mix in the graham cracker crumbs, flour, and salt until a soft dough forms that comes away from the sides of the bowl. Mix in the chocolate chips and marshmallows.
Using an ice cream scoop or a measuring cup with a ¼-cup capacity, scoop portions of dough onto the prepared baking sheets, placing them 4 inches apart. Flatten each cookie slightly, to about ¾ inch thick.
Bake one sheet at a time until the tops feel firm and the marshmallows near the edges of the cookies have melted and become clear and caramelized, about 15 minutes. (Some of the marshmallows in the center will remain white.) Cool the cookies for 5 minutes on the baking sheets, then use a wide metal spatula to transfer them to a wire rack to cool.
Use a small spoon to drizzle the chocolate coating over the cooled cookies. Leave the cookies at room temperature until the chocolate is firm, about 1 hour. Or refrigerate the cookies for about 15 minutes.
The cookies can be individually wrapped in plastic wrap and stored at room temperature for up to 2 days.