01 -
In a large bowl using a handheld or stand mixer with a paddle attachment, beat the butter, granulated sugar, and brown sugar on medium-high speed until fluffy and light in color, about 2–3 minutes. Add the egg and vanilla extract, then beat on high speed until combined. Scrape down the sides as needed.
02 -
In a separate bowl, whisk together the flour, cocoa powder, hot cocoa mix, baking soda, and salt until well combined. Gradually add the dry ingredients to the wet mixture, beating on low speed until fully incorporated. Stir in the milk. Expect a thick and sticky dough.
03 -
Cover the dough tightly and refrigerate for at least 2 hours and up to 3 days. Chilling is essential for managing the sticky consistency.
04 -
Preheat oven to 177°C (350°F). Line large baking sheets with parchment paper or silicone mats.
05 -
Scoop and roll dough into balls about 25–26g each (approximately 1 heaping tablespoon), and place them 2–3 inches apart on the prepared baking sheets. Bake for 10 minutes, then remove cookies from the oven.
06 -
Press a marshmallow half into the top of each cookie and return them to the oven for 2 more minutes. Once baked, use the back of a spoon to gently flatten the marshmallow.
07 -
Cool cookies on the baking sheet for 10 minutes, then transfer to a wire rack to cool completely.
08 -
Melt the chopped chocolate using a double boiler or the microwave. If using a microwave, heat the chocolate in 20-second increments, stirring after each, until smooth. Spoon melted chocolate over the cooled marshmallow-topped cookies.
09 -
Allow the chocolate to set at room temperature for 30-60 minutes. Once set, cookies are ready to stack, store, or gift.