Ingredients

1/2 cup (1 stick) unsalted butter, softened

1/2 cup (107 g) packed light brown sugar

1/4 cup (50 g) granulated sugar

1/2 teaspoon kosher salt

1 large egg

1 teaspoon pure vanilla extract

1/2 teaspoon baking soda

1 1/2 cups (180 g) all-purpose flour

1/4 cup (42 g) hot cocoa mix

1/4 cup (21 g) unsweetened cocoa powder

12 marshmallows, halved

2 tablespoons unsalted butter, softened

2 tablespoons unsweetened cocoa powder

Pinch of kosher salt

2 tablespoons steaming hot water

1 cup (113 g) confectioners’ sugar

Instructions

Step 1: In a large bowl, use a handheld mixer on medium-high speed to beat the softened butter, light brown sugar, granulated sugar, and salt until creamy and well combined.

Step 2: Add the egg and vanilla extract, then beat until fully incorporated. Mix in the baking soda.

Step 3: Gradually add the flour, hot cocoa mix, and unsweetened cocoa powder; beat until the dough is soft and sticky. Cover the bowl with plastic wrap and refrigerate the dough for about 2 hours to chill.

Step 4: Preheat the oven to 375°F and place a rack in the center. Line two or three baking sheets with parchment paper.

Step 5: Scoop about 1 1/2 tablespoons (around 30 g) of dough—roughly the size of a ping-pong ball—and place 8 balls per baking sheet, spacing them about 2 inches apart. If using only two sheets, keep the remaining dough balls in the bowl until ready.

Step 6: Bake the cookies for about 8 minutes until they appear puffy and matte on top. Remove the baking sheet from the oven and press a marshmallow half, cut side down, into the center of each cookie so the surface cracks slightly.

Step 7: Return the cookies to the oven and bake for 2 more minutes to soften and melt the marshmallows. Gently press each marshmallow with a small spoon to help it spread slightly. Repeat the process with remaining dough and baking sheets, replacing parchment paper as needed.

Step 8: While the cookies cool slightly, prepare the glaze. In a small bowl, whisk together the softened butter, cocoa powder, pinch of salt, and steaming hot water until smooth.

Step 9: Add the confectioners’ sugar and whisk until the glaze is free of lumps. If the glaze is too thick, add a few drops of water to thin it out. If too thin, let it rest for a minute before trying again.

Step 10: Spoon the glaze over the tops of the cookies and allow it to set before serving.

Tips & Variations

Use good quality hot cocoa mix for a richer chocolate flavor.

For extra gooey marshmallows, add an additional half marshmallow after the first melting step and bake briefly again.

Swap the confectioners’ sugar glaze for melted chocolate drizzle for a different topping.

Refrigerate dough overnight for even better flavor development.

FAQs

Can I use mini marshmallows instead of halved regular marshmallows?

Yes, mini marshmallows can be used, but they may melt more quickly and blend into the cookie. Halved regular marshmallows provide a better gooey center.

Is it necessary to chill the dough before baking?

Chilling the dough helps firm it up, making it easier to scoop and yields a chewier texture. While not absolutely required, it is highly recommended for best results.