INGREDIENTS
2 cups
unbleached all-purpose flour
1/2 cup
Dutch-processed cocoa powder
1 tsp
baking soda
1/2 tsp
salt
1 cup
light brown sugar, packed
8 tbsp
unsalted butter, room temperature
1
large egg, room temperature
1 tsp
vanilla
1 cup
buttermilk
1/4 tsp
instant espresso powder/granules
8 tbsp
unsalted butter, room temperature
1 cup
powdered sugar
1 1/2 tsp
pure vanilla extract
salt
2
(scant) cups Marshmallow Fluff