01 -
In a medium bowl, whisk together all-purpose flour, cocoa powder, baking soda, and salt until evenly combined.
02 -
Using an electric mixer, beat unsalted butter and granulated sugar in a large bowl until pale and fluffy, approximately 3 to 4 minutes.
03 -
Beat in eggs one by one, ensuring each is fully incorporated before adding the next. Stir in vanilla extract until evenly distributed.
04 -
Gradually add the dry mixture to the wet ingredients, mixing on low speed until just combined. Avoid overmixing for best texture.
05 -
Gently fold marshmallow fluff into the dough to create visible swirls, or reserve for after chilling as preferred.
06 -
Cover the dough and refrigerate for at least 60 minutes to make it easier to handle and reduce spreading during baking.
07 -
Preheat oven to 175°C. Line two baking trays with parchment paper or silicone baking mats.
08 -
Scoop out dough and roll into balls. Place on prepared trays, spacing 5 cm apart. Press an indent into each and add one teaspoon of marshmallow fluff. Swirl the fluff into the dough using a toothpick.
09 -
Bake for 10–12 minutes, or until set at the edges but soft in the center. For extra gooeyness, add more marshmallow fluff halfway through baking if desired.
10 -
Allow cookies to cool on the baking tray for 5 minutes. Transfer to a wire rack to cool completely for best texture.