Simple yet elegant, these Black and White Cookies deliver the perfect balance of soft, cake-like texture and the iconic two-tone icing for a memorable treat that’s sure to delight.
Preheat the oven to 350°F (175°C). Line a baking sheet with a silicone mat or parchment paper.
Using an electric mixer with a whisk attachment, beat the butter and sugar together until they're light and airy. Add the egg, vanilla, and sour cream, and mix until combined.
Add the flour, baking powder, baking soda, and salt, and continue mixing just until combined.
Divide the dough into 12 equal portions and place on the prepared baking sheet, leaving at least a couple of inches between the cookies to allow for spreading.
Bake the cookies for 15 minutes, or until the edges just begin to brown. Remove from the oven and place on a wire rack. While the cookies are still warm, either flip them over or press each with a glass to flatten.
Cool the cookies completely before icing them.
To make the icing and assemble:
Whisk together the confectioners' sugar, milk, corn syrup, vanilla, and salt until smooth.
Divide the icing into two bowls. Add the cocoa powder to one of the portions, and stir to combine.
Once the cookies have cooled to room temperature, pipe the vanilla icing over half of each cookie. Place the cookies in the freezer for a few minutes to let the icing set.
Next, pipe chocolate icing over the other half of each cookie. Allow the icing to set before serving.
Notes
Store in an airtight container up to 3 days or in the refrigerator up to 5 days.