Black and White Cookies

Preheat the oven to 375 degrees F (190 degrees C). Line a cookie sheet with parchment paper.

Make cookies: In a medium bowl, whisk together the cake flour, salt, and baking powder. Set aside. In a large bowl, cream together the sugar and butter using an electric mixer until light and fluffy, about 3 minutes. Add the eggs and beat for 30 seconds more. Stir in the lemon zest, vanilla extract, and lemon extract until well combined. Gradually add the flour mixture and milk in alternating 1/3 portions, mixing well after each addition until fully incorporated.

Spoon cookie dough into 1/4-cup portions onto the prepared cookie sheet.

Bake in the preheated oven until the edges just begin to turn golden brown, 13 to 15 minutes. Transfer cookies to a wire rack to cool completely.

While the cookies cool, make the vanilla icing: In a double boiler over medium heat, melt the butter. Stir in the confectioners' sugar, corn syrup, vanilla extract, and salt. Gradually add water until the icing comes together. Heat over the double boiler until the icing falls off the back of a spoon in thick ribbons, 2 to 4 minutes. Reduce heat to low.

Frost 1/2 of the flat side of each cooled cookie with vanilla icing using a rubber spatula. Allow excess to dribble back into the double boiler. Let cookies cool for 10 minutes to allow the icing to set slightly.

Meanwhile, make the chocolate icing: Return the double boiler to medium heat and add the remaining confectioners' sugar, semisweet chocolate, bittersweet chocolate, corn syrup, butter, vanilla extract, and food coloring to the remaining vanilla icing. Mix well, adding water as needed until the icing is smooth and combined. Heat until the icing falls off of the back of a spoon in thick ribbons, 2 to 4 minutes. Reduce heat to low.

Frost the other 1/2 of the cooled cookies using a rubber spatula in the same manner as before. Let the cookies cool until the icing sets completely, 1 to 2 hours.