Sourdough Black and White Cookies

These soft and cakey Sourdough Black and White Cookies, sometimes called Half-Moon Cookies, are an iconic New York City bakery staple.

The large vanilla-based cookies are iced with a shiny glaze of half chocolate and half vanilla icing, giving them a striking yin and yang appearance.

Using sourdough discard helps tenderize the cookies, store well for days, and adds a subtle tang to the sweet cookies.

The recipe guide below will walk through exactly how to make and decorate these easy cookies, including step-by-step photos and expert tips.

---

👍 Why You’ll Love This Recipe

• Cakey and soft
  • Sourdough discard helps tenderize the cookies, just like it does for biscuits, scones, and this gingerbread cake.
• Vanilla and Chocolate Flavors
  • The cookies themselves have a faint lemony vanilla flavor. However, the icing is half-and-half chocolate and vanilla so you get the best of both worlds!
• Can decorate many ways
  • While the half moon decoration is most common, it’s easy to decorate the cookies with other designs! For example, for the 2024 Total Solar Eclipse, I decorated the cookies to look like different stages of the moon and sun with waxing and waning crescents.
  • You could also decorate them with yin and yang design if you’re feeling particularly zealous.
• Store well
  • The cookies store well for days since they’re cakey and made with sourdough discard. They’re excellent cookies for bake sales, parties, or gifts.

---

🔍 Tips for Making Sourdough Black & White Cookies

• Don’t overmix the batter
  • Too much mixing leads to gluten development. It’s something you want in a sourdough bread recipe, but it will result in tougher scones, biscuits, or pancakes, if you mix the dough too much.
• Chill and rest the batter before scooping
  • Before scooping and baking the cookies, let the cookie batter rest in the refrigerator for 20 minutes. This hardens the butter in the dough so they’ll be easier to portion and won’t spread as much.
• For a shiny icing surface, use corn syrup
  • Corn syrup is the only ingredient in the cookies that may not be commonly found in your pantry. However, it’s worth it for these cookies as it helps the icing set with a shiny, reflective glaze!
• Ice with a line of vanilla icing first and let it sit
  • You’ll use the same icing base for both the vanilla and chocolate frostings. Use an offset spatula to draw a line down the center of the cookie with the vanilla frosting and ice behind the line. Then, let it rest for at least 20 minutes so that the vanilla icing sets before adding the chocolate icing.

---

🛠 Tools Needed:

See below for my tool recommendations and substitutions.

• Baking scale
  • Since the density of flour and sourdough starter may vary among individuals, it’s recommended to weigh your ingredients for accuracy. Weighing your ingredients by weight will make your baking more consistent and accurate.
• Baking sheets
  • This recipe makes 14 large cookies that spread during baking, so it’s best to bake them on at least two baking sheets. I usually use a large sheet to hold 7-8 cookies and line it with parchment paper or a silicone baking mat.
• #20 Cookie Scoop (optional but helpful)
  • This is a 3 TBS cookie scoop, or large cookie scoop. They help portion the cookies so they’re equal sizes.
• Stand mixer (optional but helpful)
  • If you don’t have a stand mixer, you can use an electric hand mixer to cream the butter and combine the ingredients with a spatula.
• Offset spatula (optional but helpful for decorating)
  • A small offset spatula is helpful to ice and decorate the cookies so they’re smooth and even. Alternatively, use a small spoon or spatula.

---

🛒 Ingredients Needed:

See below for my ingredient recommendations and possible substitutions.

Cookie Dough Ingredients

• All-purpose flour
  • These cookies are soft and tender with a cake-like base. However, using cake flour can make them too crumbly, so I recommend using all-purpose flour.
• Baking powder & baking soda
  • Mechanical leaveners that assist with browning, spreading, and their fluffy texture.
• Salt
  • Needed to bring out some of the flavors of the cookies and offset some of the sweetness.
• Unsalted butter, softened
  • Let your butter sit out for at least a couple of hours before mixing so it can come to room temperature. It won’t cream and aerate properly if it’s too cold.
• Granulated sugar
• Lemon zest (optional)
  • Lemon zest isn’t always traditional with black and white cookies, but is often added for brightness. I only use the zest of half a lemon or you verge into lemon cookie territory (not a bad thing necessarily!).
  • If you want to add a splash of lemon extract or lemon juice, you can, but I think the lemon zest actually gives the most lemony flavor.
• Vanilla extract
• Egg + Egg yolk
  • The additional egg yolk adds richness, makes them rise taller and thicker, and gives the dough a natural yellow color. If you like flatter or thinner cookies, leave it out.
• Buttermilk
  • I found that discard alone wasn’t enough moisture for the cookies to spread, so the ¼ cup of buttermilk helps keep them moist and makes them lighter and airier than sour cream or yogurt (although you could use those too). Can substitute with milk kefir or another sour milk.
• Sourdough discard (or active starter)
  • Sourdough discard is unfed sourdough starter. When I feed my starter, I store the discard in the refrigerator so there’s no waste. Learn how to make sourdough starter from scratch and my top sourdough starter tips.

Vanilla and Chocolate Icing Ingredients

• Powdered sugar, sifted
  • This is one of the few times I’ll tell you to sift an ingredient, but sifting the confectioners sugar helps break up any clumps and makes mixing the icing a breeze.
• Pinch of salt
• Light corn syrup
  • I use Karo corn syrup, which you can find in the baking aisle in most grocery stores. This is an essential ingredient in the icing so the icing stays thick, hardens slightly, and has the quintessential sheen.
  • If you don’t have or use corn syrup, you can substitute with the same amount of melted coconut oil. It won’t give you quite the same affect, but will still work.
• Vanilla extract
• Dutch process cocoa powder, sifted
  • You can use natural cocoa powder, but Dutch process is darker and has even more chocolate flavor, so the chocolate and vanilla contrast is more pronounced. If you have black cocoa, here’s a great time to use it!

---

🌗 How to Make Sourdough Black and White Cookies

Follow this visual and detailed recipe guide as you make these sourdough discard black and white cookies.

1. Mix the Dry Ingredients

In a medium-sized mixing bowl, whisk together the all-purpose flour, salt, baking powder, and baking soda.

Set the bowl aside as you mix the wet ingredients.

2. Mix the Wet Ingredients and Make the Cookie Dough

In the bowl of a stand mixer fitted with the paddle attachment (or using an electric hand mixer), cream the softened butter and sugar until light and fluffy.

On low speed, add the egg, egg yolk, lemon zest, and vanilla extract until combined. Then, pour in the sourdough discard and buttermilk and mix for a couple of minutes. Scrape the sides of the bowl to ensure all of the wet ingredients are mixed thoroughly.

Turn off the mixer and dump in all of the dry ingredients. Very slowly, pulse the batter to incorporate into the batter and mix on low speed until all of the flour is hydrated.

You should have a thick, yellow cake-like batter. Fold a few times with a spatula if needed.

3. Chill and Portion the Dough

Chill the dough for at least 20 minutes in the refrigerator*. This will help the cookies not spread too much and make portioning easier.

As the dough chills, preheat the oven to 350ºF (177ºC) with a rack in the middle. Prepare two baking sheets with parchment paper or a silicone baking mat.

Use a #20 cookie scoop (about 3 TBS) to scoop and portion out about 14 cookies onto the prepared baking sheets. These cookies spread, so be sure to space them at least a few inches apart.

If the dough is too sticky for your scoop and won’t release, use slightly floured hands to roll them out into balls and press down on them slightly to encourage some spreading.

4. Bake

Bake one sheet at a time for 14-15 minutes, or until the cake-like cookies are spongy in the middle and there’s very light browning on the bottoms. I only bake one sheet at a time for even baking.

Cool for a couple of minutes in the pan, then transfer them to a wire rack to cool completely as you bake the other pan of cookies.

5. Make the Icing

As the cookies bake and cool, make the icing.

You’ll make one batch of vanilla icing, using the same base and then add the cocoa powder for the chocolate icing after you’ve glazed the first vanilla or white icing.

To make the icing, sift the powdered or confectioners sugar in a mixing bowl and whisk in the corn syrup, two TBS of hot water (hot water helps mixing with the corn syrup so it doesn’t stiffen up too much), a pinch of salt, and vanilla extract.

Whisk until you have a thick icing that leaves a whisk trail in your bowl. If you raise the whisk above the bowl, it should leave clear lines of icing in the bowl as the image below shows.

If the icing is too thick, add splashes of water at a time. Too thin? Add a bit more confectioner’s sugar.

6. Ice the Cookies

Please note to ice the flat side of the cookies (not the domed sides).

For clean and even edges between the black and white icings, use an offset spatula and let a straight line of vanilla icing fall down the middle of the cookie. Then, fill in the rest of the cookie half with the white icing in an even layer. It’s okay if some of the icing drips down the sides.

Ice one half of all of the cookies, resting them on a wire rack, and let the vanilla icing set completely for at least 20 minutes.

Then, sift in the Dutch process cocoa powder into the remaining icing, add about another tablespoon of hot water. Whisk the chocolate icing until it’s the same consistency as the previous vanilla icing. You may need to add a little more water as the cocoa powder thickens the icing considerably more.

Once the vanilla icing is set, use your cleaned offset spatula to ice the other half of the cookies with the chocolate icing.

Finally, let the chocolate icing set for at least 20 minutes before serving!

---

How to Store

Sourdough black and white cookies store very well!

Once the icing sets, you can store the cookies in a cool airtight container for up to three days and up to five or six days in the refrigerator. The icing helps seal in some of the moisture, so they stay soft for a few days.

If adding to a cookie box, you really want to make sure the icing is completely set or they will smear onto each other. If you are stacking them on top of each other, I recommend adding a layer of parchment paper in between.

You can freeze the baked cookies for up to three months before or after glazing. Thaw in the refrigerator overnight. The icing may discolor some when thawing.

---

❓ FAQs:

---

Other Sourdough Dessert Recipes You May Enjoy:

---