I haven't made these, but it's a good cookbook.

Black and Whites
From "The Neighborhood Bakeshop" by Jill Van Cleave

Cookies:
1 cup all-purpose flour
1 cup cake flour
1/2 tsp. baking powder
1/4 tsp. salt
1 tsp. grated lemon zest
2 large eggs
3/4 cup granulated sugar
1/2 cup milk
6 Tbsp. unsalted butter, melted and cooled
1/2 tsp. vanilla extract

Frostings:
2 cups confectioner's sugar
At least 3 Tbsp. boiling water
1 ounce unsweetened chocolate, chopped
At least 1 Tbsp. light corn syrup

Preheat the oven to 350F. Grease 2 cookie sheets.

Combine the flours, baking powder, salt, and lemon zest in a small bowl and set aside.

Beat the eggs and sugar in a meduim mixing bowl until smoothly blended. Mix in the milk, melted butter, and vanilla. Slowly add the flour mixture, blending into a soft dough.

Using a 1/4 cup scoop (2 ounces), drop cookies 2 1/2 inches apart onto the prepared cookie sheets. Bake for about 15 minutes, until the top feels firm to the touch. Remove to wire racks and allow to cool to room temperature before frosting.

For the frostings, place the confectioner's sugar in a bowl. Add the boiling water and whisk to a thick, smooth, and spreadable consistency. Remove and reserve 1/3 cup of frosting; use the remainder to frost half of each cookie. If the frosting is too thick, add drops of boiling water until it is again spreadable.

Melt the chocolate in a double boiler or in a microwave on medium power for 1 to 4 minutes, checking every 30 seconds. Stir in corn syrup. Add the reserved frosting and stir to a spreadable consistency. Spread the bare half of each cookie with the chocolate frosting. If it becomes too thick, thin with additional drops of corn syrup until spreadable. Set the cookies aside until the frosting sets.

Yields 10 cookies.