INGREDIENTS
20
cupcakes
1/2 cup
dutch process cocoa powder
1/2 cup
water
2 cups
flour
3/4 tsp
baking soda
3/4 tsp
baking powder
3/4 tsp
coarse salt
16 tbsps
unsalted butter
1 1/2 cups
sugar
2 larges
egg yolk
1 3/4 tsps
vanilla extract
2/3 cup
sour cream