INGREDIENTS
1 1/4 cups
all-purpose flour
1/2 cup
unsweetened Dutch process cocoa
1 tsp
baking soda
1/4 tsp
baking powder
1/4 tsp
salt
1 1/4 cups
sugar
1/2 cup
plus 2 tablespoons (1 1/4 sticks) room-temperature, unsalted butter
1
large egg
1/4 cup
room-temperature, unsalted butter
1/4 cup
vegetable shortening
2 cups
sifted confectioners’ sugar
1/2 tsp
peppermint extract
Milk, as needed