Black and White Cookies Decorated with Edible Gold

For the cookies, preheat the oven to 350°F and line a baking sheet with parchment paper. 

Mix the 1 ¾ cups flour, baking powder, baking soda and salt in a medium bowl, then set aside. 

Using an electric mixer or a stand mixer fitted with the paddle attachment, cream together the butter, granulated sugar and brown sugar until light and fluffy. Add the vanilla and lemon extracts and mix. 

Add the egg and cream together. Gradually add some of the flour mixture and lightly mix before gradually adding the sour cream. Add more flour and repeat. It is okay if a few white streaks are visible at this point. Mix until a semi-wet dough forms. If it's TOO wet, add the 1 tablespoon of flour. On the final mix, you don't want any white streaks. 

Form into 8 to 10 balls using a scooper or your hands, place on the prepared baking sheet and bake until still pale with a light brown edge, 12 to 14 minutes. Let rest until completely cool. (You can hurry this process by placing the cookies in the freezer for 5 to 10 minutes.) 

For the black icing, mix together the confectioners' sugar and cocoa powder in a medium bowl. Stream in the milk while mixing until the icing thickens to your liking. For this cookie, the thicker, the better. Mix in the vanilla extract. 

For the white icing, mix together the confectioners' sugar and milk in a medium bowl. Mix in the vanilla and mix until you get a thick consistency. 

Flip the cooled cookies over, then ice half of each cookie with black icing and half with white. Decorate the black side with small pieces of gold leaf (if using) and sprinkle sea salt on the white side.