INGREDIENTS
1
Egg + 1 egg yolk
1/2 tsp
Baking soda
1 cup
Bread flour
1/2 cup
Brown sugar
1/2 cup
Chocolate chips, semisweet
1/3 cup
Cocoa powder, natural or Dutch-process unsweetened
1 cup
Powdered sugar
1/4 tsp
Salt
2 tsp
Vanilla
1 tsp
Apple cider vinegar
1/4 cup
Butter, unsalted
5/16 cup
Buttermilk
1/2 cup
Sour cream