These Sourdough Discard Sugar Cookie Bars are a perfect sweet treat when you don't want to spend time rolling, cutting, and baking multiple batches of cookies. Plus, you can easily customize these cookies with different colors of icing and sprinkles!
Looking for a traditional cut-out sugar cookie recipe? Try my Sourdough Discard Sugar Cookies.

Why you'll love this recipe
- These sugar cookie bars are made in one batch - no need to bake multiple batches of cookies!
- This recipe uses sourdough discard, but you can easily modify to use active sourdough starter if you prefer.
- Sugar cookie bars are very customizable - choose your icing color and top with your favorite sprinkles to make these for any birthday or celebration!
- These cookies only need to chill for 30 minutes (to make the dough easier to handle when pressing into the pan.
- Looking for other cookie bar recipes? Try these Sourdough Chocolate Chip Cookie Bars and these Sourdough Discard Halloween Kitchen Sink Cookie Bars.
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Ingredients
There are only a few key ingredients you'll need to bring this recipe together.

- Sourdough discard: The sourdough discard should be unfed and at room temperature for this recipe. This recipe is designed for a sourdough starter with a 1:1 ratio (when you feed your starter, it's with 1 part flour and 1 part water). If your starter uses a different ratio, you may need to adjust some of the ingredients in this recipe.
- Learn more about how to make a sourdough starter.
- Butter: This recipe uses quite a bit of butter, and it's important that it is softened to room temperature to cream together with the sugar properly.
- Food coloring and sprinkles: These are optional, but an easy way to customize your cookies!
See full recipe below for detailed directions.
Substitutions & Variations
This is a very adaptable recipe and below are a few easy substitutions and variations you can try.
- Use active sourdough starter - If you'd like to make this recipe with active sourdough starter, you can! To do so, omit the yeast and replace the sourdough discard with active starter (200g). You will also need to increase the rise times.
- Add sprinkles in the dough - to make a funfetti-style cookie, add ½ cup rainbow sprinkles into the dough as you're mixing.
- Customize your colors and sprinkles - Food coloring is another easy way to customize these cookies. Change the color of your icing, and add sprinkles to make these any color you like!
How to Make Sourdough Discard Sugar Cookie Bars
There are only a few key steps to bring this recipe together. The full recipe with detailed directions is at the bottom of this post.

- Step 1: In a medium mixing bowl, whisk together the flour, salt, and baking powder.

- Step 2: In a large bowl, cream together the butter and sugar until light and fluffy.

- Step 3: Mix in the sourdough discard, egg, and vanilla extract.

- Step 4: Add the dry ingredients into the wet ingredients and mix until the cookie dough forms. Cover the bowl and let chill in the refrigerator for 30 minutes.

- Step 5: Scoop the cookie dough into a 9x13-inch baking pan.

- Step 6: Press the cookie dough to the edges of the pan and fill any spaces.

- Step 7: This should be fairly smooth - it will not smooth out as it bakes.

- Step 8: Bake until lightly golden on the edges. Let the cookie bar cool completely.

- Step 9: Mix together the ingredients for the buttercream frosting. Add food coloring, if using.

- Step 10: Spread the frosting over the cookie bars, add sprinkles, slice, and serve!
Expert Baking Tips
- Use metric measurements for at least the flour and sourdough discard. These are two ingredients where there can be a huge variation in using cups vs. metric measurements. Using a kitchen scale for metric measurements for at least these two ingredients will set you on the right path!
- Make sure your butter is softened to room temperature. This will ensure that it creams together appropriately with the sugar.
- Let the dough chill for at least 30 minutes (or up to 2 days) to make it easier to press into the baking pan.
- Let the cookie bars cool completely before adding the frosting, otherwise it will melt right off.
- Looking for other cookie recipes? Try these Sourdough Lofthouse Cookies and these Sourdough Discard Chocolate Chip Cookies.
Storage
Room Temperature Storage: Store cookie bars in an airtight container at room temperature for up to 5-6 days.
Freezer Storage: Store cookie bars in a freezer-safe container or bag and freeze for up to 3 months. Before serving, let the cookies thaw to room temperature.

Recipe FAQs
They're accurate! I use the metric measurements for my own baking, especially with the flour and sourdough discard, so I recommend you do the same! There can be such a huge variation in cups measurements, particularly for those two ingredients.
It's not needed for leavening purposes, but yes, you can! To do so, replace the sourdough discard with active starter (200g). Be prepared that your cookies may rise a bit more than those made with discard.
If your frosting seems too thick, add a little bit more milk to reach your desired consistency. If it is too thin, add a bit more powdered sugar. You want the icing to be easily spreadable, but not falling off the edges of the cookie bars!
More Sourdough Discard Cookie Recipes
If you tried these Sourdough Discard Sugar Cookie Bars or any other recipe on my website, please leave a ⭐ star rating and let me know how it went in the comments below. I'd love to hear from you! Happy Baking!

Sourdough Discard Sugar Cookie Bars
Equipment
- Parchment paper optional
Ingredients
For the Cookies
- 2 ⅔ cup all-purpose flour
- ½ teaspoon kosher salt
- ½ teaspoon baking powder
- 14 Tablespoons unsaltes butter softened
- 1 cup granulated sugar
- 200 grams (about ¾ cup) sourdough discard unfed, at room temperature
- 1 egg
- 2 teaspoons vanilla extract
For the Frosting
- ¾ cup unsalted butter softened
- 2 ⅔ cup confectioner's sugar
- 1 ½ teaspoons vanilla extract
- 3-4 Tablespoons milk non-dairy or regular dairy
- Food coloring optional
- Sprinkles optional
Instructions
- In a medium bowl, mix together the flour, salt, and baking powder. Set aside.
- In a large bowl using a hand-held mixer, beat together the butter and sugar until light and fluffy, about 2-3 minutes. Add the sourdough discard, egg, and vanilla extract and mix until combined.
- Add the dry ingredients to the wet ingredients and mix until combined, and a smooth dough forms. Cover the mixing bowl with plastic wrap. Chill in the refrigerator for 30 minutes (or up to 2 days).
- Preheat the oven to 350℉ and line a 9x-13inch baking pan with parchment paper (optional, but it makes it easier to get the baked bars out of the pan).
- Using a large cookie scoop or spoon, roughly scoop the cookie dough into the baking pan. Use your hands or a spatula to evenly press the cookie dough to the edges of the pan and fill any spaces.The dough will not spread much, so you want this to be pressed fairly flat and even. We will cover it with frosting, too, so don't worry too much!
- Bake for 25-30 minutes until lightly browned at the edges. Let cool in the baking pan for at least 10 minutes, then transfer to a cooling rack to cool fully.
- Once the cookie bars are fully cooled, cream the butter in a medium-sized bowl until light and fluffy, 2-3 minutes, then slowly mix in the confectioner's sugar. Add the vanilla extract and milk (start with 3 Tablespoons), mixing until fully smooth and incorporated. Add more milk if you feel that the frosting is too thick. If using food coloring, add a few drops and mix until you reach your desired color.
- Spread the cookie bars with a layer of frosting, add sprinkles (optional), then cut into 20 pieces, and serve!






Jessica Vogl says
Soooo delicious and so easy to make! Love that I can make these any color for any party or holiday!