01 -
In a medium bowl, stir together salt, soda, cocoa, and flour until evenly blended.
02 -
Use an electric mixer to whip the butter and sugar together for 3-4 minutes till it looks airy and pale.
03 -
Mix in vanilla and eggs, one by one, making sure each is fully incorporated.
04 -
Slowly combine the dry bowl into the wet mixture. Stop mixing once it just comes together. Chill for at least an hour.
05 -
Scoop into balls, press indents, add marshmallow fluff, and swirl it around. Pop in the oven at 350°F for 10-12 minutes.