INGREDIENTS
1
Egg, large
1/2 cup
All-purpose flour
1/2 tsp
Baking powder
1/4 cup
Cocoa powder, unsweetened Dutch-process
1/3 cup
Dark chocolate
1 cup
Powdered sugar
1/4 tsp
Salt
1/2 cup
Sugar
1 tbsp
Vanilla extract
1 tsp
Espresso
2 tbsp
Butter, unsalted