Marshmallow Choco Cookies

Instructions

Start by creaming together the softened butter, granulated sugar, and brown sugar until they're fluffy and light in color. It usually takes about 2–3 minutes. Add the egg and vanilla extract, then beat until well combined. Scrape down the sides of the bowl as needed.
In another bowl, whisk together the flour, cocoa powder, hot cocoa mix, baking soda, and salt until everything's combined. Add these dry ingredients to the wet mixture. Beat on low until they're combined. The dough will be thick. Finally, mix in the milk until well incorporated. The dough will be thick and a bit sticky.
Cover the dough tightly and let it chill in the refrigerator for at least 2 hours, up to 3 days. This step is important because the dough is sticky.
Preheat your oven to 350°F (177°C) and line large baking sheets with parchment paper or silicone baking mats.
Once chilled, scoop and roll the dough into balls, about a heaping 1 tablespoon each. Place them 2–3 inches apart on the prepared baking sheets.
Bake the cookies for just 10 minutes. Then, take the cookies out and press a marshmallow half lightly into the top of each cookie. Return them to the oven and bake for an additional 2 minutes. Once out of the oven, gently press down on the marshmallow with the back of a spoon to slightly flatten it.
Let the cookies cool on the baking sheet for 10 minutes, and then transfer them to a wire rack to cool completely.

Now, melt the chocolate. You can do this using a double boiler or in the microwave. If using the microwave, place the chopped chocolate in a heat-proof bowl and microwave it in 20-second intervals, stirring between each until it's melted and smooth. Spoon the melted chocolate over each cooled cookie topped with marshmallow.
Allow the chocolate to set at room temperature for 30-60 minutes. Once set, you can store the cookies at room temperature in an airtight container for up to 1 week.