01 -
In a medium bowl, whisk together all-purpose flour, unsweetened cocoa powder, baking soda, and salt until thoroughly blended.
02 -
In a large mixing bowl, use an electric mixer to cream together unsalted butter and granulated sugar for 3–4 minutes until light and fluffy.
03 -
Beat in the eggs, one at a time, ensuring each is fully mixed, then stir in vanilla extract until smooth.
04 -
Gradually add the dry ingredients into the wet mixture on low speed, mixing just until a cohesive dough forms.
05 -
Cover the dough and refrigerate for at least 1 hour to make shaping easier and help prevent excessive spreading during baking.
06 -
Preheat the oven to 350°F (175°C) about 20 minutes before baking. Line two baking sheets with parchment paper or silicone baking mats.
07 -
Using a cookie scoop or tablespoon, portion out balls of chilled dough. Arrange on prepared baking sheets, spacing about 2 inches apart. Press a small indentation in the center of each dough ball and add a teaspoon of marshmallow fluff. Swirl gently using a toothpick.
08 -
Bake in the preheated oven for 10–12 minutes until edges are set and centers remain soft. Optionally, add extra marshmallow fluff halfway through baking for added gooeyness.
09 -
Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely and allow the marshmallow to partially set.