Ingredients:
• 3 cups all-purpose flour
• ½ teaspoon baking soda
• ½ teaspoon baking powder
• ½ teaspoon salt
• 1 ¾ sticks (198 g) butter
• 1 ¼ cups sugar
• 2 large eggs
• 1 large egg yolk
• ¾ cup buttermilk
• 1 tablespoon pure vanilla extract
• 1 tablespoon freshly grated lemon zest
• 4 cups confectioners' sugar
• ¼ cup milk
• 3 tablespoons heavy cream
• 2 teaspoons pure vanilla extract
• Red no-taste gel food coloring
Method:
To make cookies:
- Preheat oven to 350°F (176°C). Sift flour, baking soda, baking powder, and salt into a large bowl.
- In the bowl of an electric mixer fitted with a paddle attachment, cream butter and sugar until fluffy (about 2 minutes). Scrape down the bowl and add eggs and egg yolk one at a time, beating briefly after each addition. Scrape down the bowl again, and turn mixer to low. Add the flour mixture in 3 parts, alternating with the buttermilk in 2 parts. Scrape down the bowl; add vanilla and lemon zest, and mix on low speed for a few more seconds.
- Using an ice cream scoop (about ¼ cup), drop dough onto parchment-lined baking sheets spaced about 3 inches apart (6 cookies per sheet).
- Bake for 17 minutes, rotating sheets between oven racks halfway through, until edges are golden brown and tops spring back when gently touched. Remove from oven and let sit for 5 minutes, then remove cookies and cool on racks.
To make frosting:
- In a large bowl, whisk together confectioners' sugar, milk, and cream. If mixture is too thick, add a little more milk (by the teaspoon until desired consistency is reached). Pour half of the frosting (about ¾ cup) into another bowl and add vanilla and red food coloring until desired red color is reached.
- Use an offset spatula to spread red frosting on half of the top of each cookie. Let stand until almost set, 20 minutes. Using a clean spatula, spread white frosting over unfrosted half of each cookie. (If the frosting thickens up during the process, whisk until loose.) Let set completely, about 1 hour.
http://www.oprah.com/food/Red-and-White-Cookies