top-heavy heavenly hash

In plain view, right on top—that is where the heap of marshmallows, walnuts, and chocolate chips sits on these crisp chocolate cookies. If I had the good luck to see a cookie like this one in a bakery case, I’d buy them all.

makes 14 cookies cookie making 15 minutes cookie baking 325 degrees, two baking sheets for about 14 minutes each

11/3 cups (8 ounces) semisweet chocolate chips

11/3 cups (about 5½ ounces) walnuts, coarsely chopped

1 cup unbleached all-purpose flour

¼ cup unsweetened Dutch-process cocoa powder

1 teaspoon baking soda

½ teaspoon salt

½ cup (1 stick) unsalted butter, melted

1 cup sugar

1 large egg

1 teaspoon vanilla extract

cups miniature marshmallows

Position a rack in the middle of the oven. Preheat the oven to 325 degrees. Line two baking sheets with parchment paper.

In a medium bowl, stir the chocolate chips and walnuts together; set aside. Sift the flour, cocoa powder, baking soda, and salt into a small bowl and set aside. In a large bowl, using a large spoon, stir the melted butter and sugar to blend them. The mixture will look grainy. Stir in the egg and vanilla until the mixture looks smooth and shiny. Stir in the flour mixture to incorporate it.

Drop heaping tablespoons (about 3 level tablespoons each) of dough onto the prepared baking sheets, spacing them 4 inches apart. Bake one sheet of the cookies until the tops feel firm, about 14 minutes. The cookies will puff up during baking, then flatten.

Remove the hot cookies from the oven and, leaving a ½-inch plain edge all around, scatter about 12 marshmallows over each cookie. Sprinkle 2 tablespoons of the walnut–chocolate chip mixture over the marshmallows. Return the cookies to the oven, immediately turn off the oven, and leave the cookies in the oven for 5 minutes. Remove the cookies. The marshmallows will be soft and the chocolate chips will be melted but hold their shape. Cool the cookies for 10 minutes on the baking sheet, then use a wide metal spatula to transfer the cookies to a wire rack to cool thoroughly. Preheat the oven again and bake and top the second sheet of cookies.

The cookies can be stored in a tightly covered container at room temperature for up to 3 days.