01 -
Set the oven to 175°C and line two baking sheets with parchment paper.
02 -
Whisk together flour, cocoa powder, baking soda, and salt in a medium bowl.
03 -
Beat softened butter and granulated sugar in a separate bowl until light and fluffy.
04 -
Incorporate the egg and vanilla extract into the butter mixture, mixing thoroughly.
05 -
Gradually add dry ingredients to the wet mixture, stirring until just combined.
06 -
Gently fold in the semi-sweet chocolate chips and mini marshmallows to the dough.
07 -
Drop spoonfuls of dough onto the prepared baking sheets and bake for 10 to 12 minutes until edges are set.