New York Black and White Cookies

Before you start

The black and white cookie is a New York bakery fixture: a big, soft, lightly lemony cake-like cookie, iced on its flat underside with a glossy vanilla half and a chocolate half. It is closer to a thin cake than a crisp cookie, so the batter looks like a thick cake batter and uses milk and both baking powder and baking soda for a tender, springy crumb.

The icing is the defining part. It is a pourable sugar icing, not frosting, set with a little corn syrup for shine. Ice the flat bottom, which is smoother than the domed top, and work in order: vanilla first, let it set, then chocolate, so you get a clean line down the middle. Make the icing thick enough to coat without running off the edges; you can always loosen it with a few drops of hot water.

Ingredients

• Cookies115 g (½ cup) unsalted butter — softened
• 200 g (1 cup) granulated sugar
• 2 large (about 100 g) eggs — room temperature
• 1 tsp vanilla extract
• 1 tsp finely grated lemon zest
• 280 g (2¼ cups, spooned and leveled) all-purpose flour
• ½ tsp baking powder
• ½ tsp baking soda
• ½ tsp fine salt
• 120 ml (½ cup) whole milk — room temperature
• Icing360 g (3 cups) powdered sugar — sifted
• 1 tbsp light corn syrup
• ½ tsp vanilla extract
• 60 to 75 ml (4 to 5 tbsp) hot water
• 30 g (1 oz) unsweetened chocolate — melted

Method

1. Heat the oven to 190°C (375°F) and line two baking sheets with parchment. Whisk the flour, baking powder, baking soda and salt in a bowl.
2. Beat the butter and sugar on medium speed for 3 minutes, until light and fluffy. Add the eggs one at a time, then the vanilla and lemon zest, beating until smooth.
3. On low speed, add the dry ingredients in three parts, alternating with the milk in two parts. Mix just until smooth; the batter will be thick and spoonable.
4. Scoop ¼ cup (about 65 g) of batter per cookie, six per sheet, at least 8 cm (3 in) apart. Spread each mound into a 6 cm (2½ in) round with the back of a wet spoon.
5. Bake one sheet at a time for 14 to 16 minutes, until the edges are lightly golden and the tops spring back when pressed. Cool on the sheet for 5 minutes, then cool completely on a rack, flat side down.
6. For the icing, stir the powdered sugar, corn syrup, vanilla and 60 ml (4 tbsp) hot water into a thick, smooth glaze that slowly falls from the spoon in a ribbon. Add more hot water by the teaspoon if needed.
7. Turn the cookies flat side up. Spread vanilla icing over half of each one with the offset spatula, using a light hand at the edge. Let it set for 15 minutes.
8. Stir the melted chocolate into the remaining icing with another 1 to 2 teaspoons hot water so it matches the first icing's thickness. Ice the other half of each cookie, meeting the vanilla edge cleanly. Let the cookies set for about 45 minutes, until the icing is dry to the touch.

Tips for success

• Keep the icing bowls covered with a damp towel while you work; a crust forms quickly.
• If the icing thickens as it sits, set the bowl over a pan of hot water for a minute and stir.
• Use a straight-edged spatula and draw the dividing line first, then fill in the rest of each half.

Substitutions

All-purpose flour

Use 260 g cake flour for a softer, finer crumb closer to some bakery versions. The cookies spread a little more.

Whole milk

Buttermilk gives a slight tang and a more tender cookie. Keep the baking soda as written; it reacts with the acid for lift.

Unsweetened chocolate

Use 2 tablespoons Dutch-process cocoa sifted into the icing with an extra tablespoon of hot water. The chocolate half will be darker and less glossy.

Variations

Half-moon minis

Portion 1 tablespoon of batter per cookie, bake for 8 to 10 minutes, and ice them the same way for about 36 small cookies.

Lemon icing

Swap the hot water in the vanilla icing for warm lemon juice for a sharper, brighter white half.

Troubleshooting

Icing runs off the sides

It is too thin. Stir in more sifted powdered sugar a tablespoon at a time until it falls in a slow ribbon.

Icing looks dull and crackly

It was too thick or set too fast. Add a few drops of hot water and the corn syrup, and ice the cookies at room temperature.

Cookies are domed and dry

Too much flour or too long in the oven. Weigh the flour, spread the batter mounds slightly and remove the cookies as soon as the tops spring back.

Cookies ran into each other

Too many on a sheet. Bake six at a time and leave 8 cm between them; they spread to about 10 cm.

Storage

Store iced cookies in a single layer in an airtight container at room temperature for up to 3 days. Wrap individually in plastic, as delis do, to keep them soft. Freeze un-iced cookies for up to 2 months and ice after thawing.

Safety notes

Contains wheat, egg, milk and corn syrup. Do not eat the batter raw; it contains uncooked eggs and flour.