Black and White Cookies

• Heat oven to 375° Fahrenheit.
• Line three rimmed baking dishes with parchment paper.

Prepare cookies

• In a large bowl, whisk together flour, baking powder, sea salt, and baking soda. In a medium bowl, whisk together sour cream (or yogurt), milk, vanilla, lemon zest, and almond extract.
• In the bowl of an electric mixer fitted with a paddle, beat together butter and sugar at high speed until light and fluffy, about 5 minutes. Beat in eggs, one at a time, scraping the sides of the bowl as necessary.
• Reduce the mixer speed to low and beat in ⅓ of flour mixture, then ⅓ of sour cream mixture. Repeat, scraping the sides of the bowl as necessary, until both mixtures are incorporated. The mixture should have the consistency of thick poundcake batter.
• Place scant ¼-cup scoops of batter onto prepared baking sheets, spacing them 2 inches apart. A taller mound seems to give a more circular cookie, a flatter mound seems to give more irregularly shaped ones. You should have 14 cookies.
• Bake for 6 minutes. Rotate baking sheets. Continue baking until the cookies are just firm and spring back when light pressed in the center, about 6-9 minutes more. The cookies should only brown on the bottom, if at all. Do not overbake or they will dry out.
• Transfer baking sheets to wire racks. Cool for 15 minutes, then transfer cookies to racks and cool them completely.

Prepare glaze and glaze cookies.

• Prepare vanilla glaze: Once the cookies have cooled, place confectioners' sugar in a medium bowl. Whisk in 3 tablespoons boiling water, corn syrup, vanilla, and salt. Continue to whisk and add more boiling water as needed, ½ teaspoon at a time, until the glaze is thick yet spreadable, with the texture of hot fudge sauce.
• Apply vanilla glaze: On the flat side of each cookie, spread the glaze. Glaze only half of the surface; you will put the chocolate glaze on the other half. As you glaze each cookie, place it on a wire rack to set. You should have vanilla frosting left.
• Prepare chocolate glaze: Whisk the melted chocolate into the vanilla glaze. Whisk in cocoa and enough room temperature water to make a thick yet spreadable glaze.
• Apply chocolate glaze: Spread chocolate glaze over the remaining half of each cookie. Return cookies to wire rack and let glaze set for at least 1 to 2 hours.