01 -
In a medium bowl, whisk together all-purpose flour, unsweetened cocoa powder, baking soda, and salt until fully blended.
02 -
In a large mixing bowl, use an electric mixer to beat unsalted butter with granulated sugar until pale and fluffy, approximately 3 minutes.
03 -
Add eggs one at a time to the butter mixture, mixing well after each addition. Stir in the vanilla extract.
04 -
Gradually mix the dry ingredients into the wet mixture on low speed just until a soft dough forms. Avoid overmixing. Swirl in the marshmallow fluff lightly, or reserve for filling after chilling.
05 -
Cover the dough and refrigerate for at least 1 hour to firm up and prevent excessive spreading during baking.
06 -
Preheat the oven to 175°C. Line two baking sheets with parchment paper or silicone baking mats.
07 -
Scoop portions of chilled dough with a cookie scoop or tablespoon and roll into balls. Place spaced apart on prepared baking sheets. Press an indent in the center of each, fill with a teaspoon of marshmallow fluff, and gently swirl the filling with a toothpick.
08 -
Bake for 10–12 minutes until the edges are set but centers remain soft. Optionally, add extra marshmallow fluff to the tops halfway through baking for a gooier texture.
09 -
Allow to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely before serving.