Black and White Cookies

Step 1
Preheat the oven to 375 degrees F (190 degrees C). Line a cookie sheet with parchment paper.

Step 2
Mix flour, baking powder, and salt together in a medium bowl.

Step 3
Cream sugar and butter together in a large bowl using an electric mixer for 3 minutes. Add eggs and beat for 30 seconds more. Add lemon zest, vanilla extract, and lemon extract. Mix together. Add flour mixture and milk gradually in equal 1/3 proportions, mixing batter well after each addition until fully incorporated.

Step 4
Spoon cookie batter out 1/4-cup portions onto the prepared cookie sheet.

Step 5
Bake in the preheated oven until edges just begin to turn golden brown, 13 to 15 minutes. Transfer cookies to a wire rack to cool completely.

Step 6
While cookies cool, melt butter for vanilla icing in a double boiler over medium heat. Stir in confectioners' sugar, corn syrup, vanilla extract, and salt. Add water gradually until vanilla icing comes together. Heat over the double boiler until icing falls off the back of a spoon in thick ribbons, 2 to 4 minutes. Set heat to low.

Step 7
Frost 1/2 of the golden brown underside 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.

Step 8
Meanwhile, set the double boiler back to medium heat and add confectioners' sugar, semisweet chocolate, bittersweet chocolate, corn syrup, butter, vanilla extract, and food coloring to the remaining vanilla icing. Mix well, adding water until icing is combined. Heat until icing falls off of the back of a spoon in thick ribbons, 2 to 4 minutes. Set heat to low.

Step 9
Frost the other 1/2 of the cooled cookies using a rubber spatula in the same manner as before. Let cookies cool until icing sets, 1 to 2 hours. Serve.