INGREDIENTS
1/2 cup
unsalted butter
3/4 cups
sugar
1 large
egg
1/2 cup
sour cream
1 tsp
vanilla extract
1 1/2 cups
all purpose flour
1 tbsp
cornstarch
1/2 tsp
baking powder
1/4 tsp
baking soda
1/4 tsp
salt
1/2 cup
unsalted butter
1 tbsp
shortening
1 tsp
vanilla extract
2 1/2 cups
powdered sugar
1 pinch
salt
3 tbsp
heavy cream
1 serving
sprinkles
1