New York Black and White Cookie

A New York speciality, these cookies taste best the day after they are made. I used a recipe from Martha Stewart's Baking Handbook, one of the best all-round baking guides/cookbooks I've come across.

You will need (for cookies):
3 cups all-purpose flour
1/4 tsp baking powder
1/4 tsp baking soda
1/4 tsp salt
10 tbsp unsalted butter
1/2 cup vegetable shortening
1 cup, plus 3 tbsp sugar
2 large whole eggs, plus 1 egg yolk
1 tbsp pure vanilla extract

Preheat the oven to 350 degrees Farenheit. Line two baking sheets with parchment paper and set aside. In a bowl, whisk together the flour, baking powder, baking soda, and salt.

Using an electric mixer, beat the butter, shortening, and sugar, scraping down the sides of the bowl as needed, until light and fluffy. Add whole eggs and egg yolk one at a time; beat until combined after each addition. Beat in the vanilla. Add the flour mixture in two batches, alternating with the cream. Beat until just combined (do not overmix).

Use a 1/4-cup measure to scoop dough 3 inches apart onto the prepared sheets. Bake, rotating sheets halfway through, until the edges just begin to turn golden brown and the centers are cakey and tender, about 10-12 minutes. Remove the cookies from the parchment and let cool completely.

You will need (for icing):

1 cup heavy cream

3 1/2 cups confectioners' sugar

5 tbsp Dutch-process cocoa powder

6 tbsp boiling water

In a clean bowl, whisk the cream into sugar until smooth. Set aside 1 1/4 cups (for white icing). Combine cocoa with boiling water and stir until dissolved. Add to remaining mixture, and stir to combine (for black icing). Use immediately.