INGREDIENTS
4 tsp
Key lime, zest
3 tbsp
Key lime, fresh juice
3/4 tsp
Key lime extract
1
Egg plus one egg yolk, large
1 3/4 cups
All-purpose flour
1 tsp
Baking powder
1/2 tsp
Baking soda
1/4 cup
Brown sugar, light
4 1/2 cups
Confectioners' sugar
1/2 cup
Granulated sugar
3/4 tsp
Salt
1/2 cup
Butter, unsalted
1/2 cup
Butter, unsalted very soft
1
block Cream cheese, full-fat very soft
1 cup
Sour cream, full-fat