Approximate Yield: 30 Cookies, 36 cookies worth of Vanilla Glaze, 48 cookies worth of Chocolate Glaze
240g All-Purpose Flour
210g Cake Flour
3g Baking Powder
3g Salt
254.3g Unsalted Butter (Softened)
297g Granulated Sugar
200g Egg
7g Vanilla Extract
2g Freshly Grated Lemon Zest
170.3g Buttermilk
380g Powdered Sugar
28.4-42.6g Hot Milk or Water, plus additional as needed
19.5g Light Corn Syrup
2.3g Vanilla Extract
0.4g Salt
42.5g Unsweetened Chocolate, Coarsely Chopped
42.5g Semi-Sweet Chocolate, Coarsely Chopped
14.1g Unsalted Butter
190g Powdered Sugar
28.4g Boiling Water, plus additional as needed
19.5g Light Corn Syrup
3.5g Vanilla Extract
Heat the oven to 350°. Line two cookie sheets or flat baking trays with parchment paper, set aside.
Sift or stir together the all-purpose and cake flours, the baking powder, and the salt. Set aside as well.
In a bowl of an electric mixer fitted with the paddle attachment, cream together the butter on medium speed until smooth and lightened in color. Add the sugar and mix for about 5 minutes to thoroughly incorporate. Mix in the eggs on at a time, stirring 30 seconds after each addition. Scrape down the bowl as needed. Mix in the vanilla and the lemon zest.
Blend in the flour mixture, adding it alternately with the buttermilk, starting and ending with the dry ingredients. Do not over-mix the batter.
Using a medium ice cream scoop, drop six mounds of dough onto the prepared cookie sheets, spacing them 3 to 4 inches apart. Bake the cookies for 20 to 30 minutes, or until the edges are lightly browned. To ensure even browning, half-way through baking rotate the sheets top to bottom and front to back. Remove the cookies from the oven and let rest on the pan for 5 minutes before loosening with a large metal spatula. Cool on wire racks. While the cookies are cooling make the glazes.
Starting with the vanilla glaze, use a small offset metal spatula, or a butter knife, to outline the dividing point in the center where the two flavors on each cookie will meet. Fill the remaining half of the cookie with the vanilla glaze, applying it as smoothly as you can. After the vanilla glaze has set and each cookie is covered, apply the chocolate glaze on the unglazed half, again starting at the dividing point and applying it as smoothly as you can. Let the glaze set before storing or eating the cookies. Enjoy!
*Storage: Store in an airtight container, layered between strips of wax paper, for up to 2 weeks. These cookies may be frozen, preferably before glazing.
Place the powdered sugar in a large bowl and add the remaining ingredients. Stir with a small whisk or spoon until very smooth. The glaze should pour from the spoon in a steady stream. Use additional liquid sparingly, until you reach desired consistency. A little bit goes a long way.
Melt the chocolates and butter in a shallow bowl set over simmering water, or in the microwave in 20 second bursts, mixing after each; stirring until smooth. Remove from the heat and add the sugar alternately with the water. Stir in the corn syrup and vanilla extract. Beat well with a wooden spoon or whisk until very smooth. If the glaze is too thick add a bit for hot water, until desired consistency is reached.