INGREDIENTS
1
Egg, large
1/2 tsp
Baking soda
1/2 cup
Cocoa powder, unsweetened
1/4 cup
Cocoa powder, dark
2 1/4 cups
Flour
1 cup
Granulated sugar
1/2 tsp
Kosher salt
1 1/2 cups
Powdered sugar
1 1/4 tsp
Vanilla
1/3 cup
Vegetable oil
1/2 cup
Butter, unsalted
3 tbsp
Milk
1/2 cup
Sour cream