Key lime cookies

1/2 cup butter

1 cup sugar

1 egg

1 egg yolk

1 1/2 cups flour

1 tsp baking powder

1/4 cup key lime juice

1 1/2 tsp lime zest

1/2 cup powdered sugar

Mix all ingredients except powdered sugar. Refrigerate at least 1 hour. Roll into 1 inch balls place on greased cookie sheet. Bake 8 to 10 minutes. Sprinkle with powdered sugar.