01 -
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy (about 3 minutes). Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.
02 -
In a separate bowl, whisk together the flour, cocoa powder, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
03 -
Fold in the semi-sweet chocolate chips. Cover the dough and refrigerate for at least 30 minutes to firm up.
04 -
Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper. Scoop out about 2 tablespoons of dough and flatten it slightly in your hand. Place 1 teaspoon of Nutella in the center, followed by 1 teaspoon of marshmallow fluff. Press the edges gently to partially seal, leaving a small gap for the marshmallow to puff out. Top with another flattened tablespoon of dough and seal the edges.
05 -
Bake for 10-12 minutes, or until the cookies are slightly cracked on top. The marshmallow fluff will spread into a smooth, gooey layer inside. Let the cookies cool on the baking sheet for 5 minutes before transferring to a cooling rack.