INGREDIENTS
1
Egg, large
1 cup
All-purpose flour
1/2 tsp
Baking soda
1/4 cup
Cocoa powder, unsweetened
1/3 cup
Granulated sugar
1/4 tsp
Kosher salt
1 cup
Powdered sugar
1/2 tsp
Vanilla extract
1/4 cup
Oil
2 tbsp
Milk
1/2 cup
Sour cream
about 2 tablespoons rainbow sprinkles (optional garnish)