Ingredients
Method
- In a large bowl, use a handheld or stand mixer fitted with a paddle attachment to beat the softened butter, granulated sugar, and brown sugar together on medium-high speed for about 3 minutes, until the mixture is pale, fluffy, and noticeably increased in volume.
- Add the egg and vanilla extract to the creamed mixture, then beat on high speed until fully combined and silky, scraping down the sides and bottom of the bowl as needed.
- In a separate bowl, whisk together the flour, cocoa powder, dry hot cocoa mix, baking soda, and salt until evenly distributed with no streaks.
- Pour the dry ingredient mixture into the bowl with the creamed butter mixture and beat on low speed just until a thick dough forms, then add the milk and beat again briefly until incorporated — the dough will be dense and slightly sticky.
- Wrap the dough tightly with plastic wrap or press it into an airtight container, then refrigerate for a minimum of 2 hours and up to 3 days before baking.
- When ready to bake, preheat your oven to 350°F (177°C) and line two large baking sheets with parchment paper or silicone baking mats.
- Remove the chilled dough from the refrigerator and use a tablespoon-sized cookie scoop to portion out heaping 1-tablespoon balls (about 25–26g each), rolling them lightly between your palms until smooth, then space them 2–3 inches apart on the prepared baking sheets.
- Slide the cookies into the preheated oven and bake for 10 minutes, then remove the pan, quickly press one marshmallow half cut-side down into the center of each cookie, and return the pan to the oven for 2 additional minutes.
- Pull the cookies from the oven and use the back of a spoon to gently press each marshmallow down slightly so it spreads into a flatter disc shape, then leave the cookies to cool on the pan for 10 minutes before transferring them to a wire rack to cool completely.
- Melt the finely chopped baking chocolate in a microwave-safe bowl in 20-second bursts, stirring well between each interval, until the chocolate is completely smooth and glossy or melt it over a double boiler on the stovetop.
- Spoon or drizzle the melted chocolate generously over the marshmallow tops of each fully cooled cookie, then allow the chocolate to set at room temperature for 30–60 minutes before stacking or storing.
Nutrition
Notes
These cookies were made for cold evenings and warm company. The secret marshmallow hidden under a river of chocolate makes every bite feel like a little surprise worth savoring. Make the dough ahead, chill overnight, and bake fresh when the moment calls for something truly special.