Sourdough Sugar Cookie Bars
Sourdough sugar cookie bars with vanilla frosting are a breeze to make and consistently steal the show at any party!
Customize the sprinkles for the perfect dessert to celebrate the holidays or any special occasion.
These irresistible sourdough cookie bars have a soft and chewy texture with a hint of tanginess from the addition of sourdough starter.
Just like our sourdough graham crackers for s'mores, sourdough chocolate chip cookies, and sourdough thumbprint cookies, they are easy to make and sure to satisfy your sweet cravings.
Whether you're a beginner or an experienced baker, this recipe is simple to follow and guarantees delicious results. Give it a try and enjoy these delightful treats!
Ingredients needed to make sourdough sugar cookie bars
For the cookie dough you will need:
- all-purpose flour
- sourdough starter discard
- butter
- sugar
- eggs
- vanilla extract
- salt and baking powder
Pro Baking Tip
If you're not a frequent baker, it's a good idea to check the expiration date on your baking powder container. Baking powder tends to lose its potency after approximately 6 months from the time it's been opened. Ensuring that your baking powder is fresh will help you achieve the best results in your baked goods.
For the frosting you will need:
- room temperature butter
- powdered sugar
- vanilla extract
- heavy cream
How to make sourdough sugar cookie bars
Before you start, prepare an 8" x 8" baking tin by lining it with parchment paper. For easier handling, crumple the parchment paper first to make it more pliable, then smooth it out and line the baking dish.
If you plan to bake the cookie bars right away, transfer the oven rack to the center position and preheat your oven to 350°F (176°C).
Step 1: Make the cookie dough
This step can be done with an electric hand mixer, a stand mixer, or a stiff spatula.
In a large mixing bowl, use an electric mixer to blend the butter and sugar for 2-3 minutes or until they achieve a light and fluffy consistency. Add the egg, vanilla extract, and sourdough starter discard, and continue to beat the mixture until all the wet ingredients are thoroughly combined.
Combine the flour, baking powder, and salt with the wet ingredients and continue mixing them until the batter just comes together.
Take a spatula and scrape the sides of the bowl to ensure that all the ingredients have been thoroughly combined.
Step 2: Bake
Evenly distribute and press the cookie dough into the bottom of the tin. To prevent the dough from sticking to your hands, apply a light dusting of flour.
If you don't plan on baking the cookies immediately, cover the dough and store it in the refrigerator for a maximum of three days.
Place the cookies in the oven and bake them for approximately 15-18 minutes, or until a toothpick inserted into the center emerges clean. The surface of the cookie bars should be a light golden color.
Take the tin out of the oven and transfer it to a wire cooling rack. Let the cookie bars cool down entirely in the tin before applying the frosting.
Step 3: Make the frosting
Combine the powdered sugar, vanilla extract, heavy cream, and butter in a bowl and use an electric mixer to beat them together until a smooth and creamy consistency is achieved.
In case the frosting is too thick, gradually add a teaspoon of heavy cream at a time until the desired consistency is reached.
On the other hand, if the frosting is too thin, incorporate a few tablespoons of powdered sugar and mix well to adjust the consistency accordingly.
Step 4: Decorate
Use an offset spatula to generously spread the frosting, making sure to coat every inch. Lastly, top it with a variety of sprinkles for a finishing touch.
Once you are ready to serve the sourdough sugar cookie bars, use the parchment paper to help lift the cookie bar out of the tin and cut it into squares.
This recipe yields 9 generously sized sourdough sugar cookie bars or 18 smaller bars. Whether you prefer larger portions or smaller bites, you have the flexibility to adjust accordingly.
Customize
Whether you're making these sugar cookie bars for the holidays or a special occasion, personalize the sprinkles to suit the theme or mood of your celebration.
Today we are celebrating the Fourth of July so we chose a red, white, and blue color scheme.
How to Store
To maintain freshness, store the squares in the refrigerator in a covered container for up to five days.
For longer-term storage, with optimal taste and texture, freeze them. Begin by placing the squares in a single layer on a baking sheet and freezing them for an hour.
Afterward, transfer the partially frozen cookies to a freezer-safe container, separating each layer with parchment paper.
By following these steps, you can enjoy your cookies at a later time for up to a month.
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Sourdough Sugar Cookie Bars
Before You Begin
INGREDIENTS
Dough ingredients
- 8 tablespoons (112 g) softened unsalted butter
- ¾ cups (150 g) granulated white sugar
- 1 large egg (room temperature)
- 2 teaspoons (5 g) vanilla extract
- ¼ cup (50 g) sourdough starter discard (room temperature)
- 2 cups (240 g) all-purpose flour
- ½ teaspoon fine sea salt
- ½ teaspoon baking powder
Frosting ingredients
- 4 tablespoons (56 g) softened butter
- 1 cup powdered sugar
- ½ teaspoon vanilla extract
- 1 tablespoon heavy cream
Topping
- sprinkles
INSTRUCTIONS
Make the Cookie Dough
- If you plan to bake the cookie bars right away, preheat your oven to 350°F (176°C).
- Use an electric or stand mixer to cream 8 tablespoons (112 g) softened unsalted butter and ¾ cups (150 g) granulated white sugar for 2–3 minutes until light and fluffy. Add 1 large egg, 2 teaspoons (5 g) vanilla extract, and ¼ cup (50 g) sourdough starter discard, then mix until fully combined.
- Add 2 cups (240 g) all-purpose flour, ½ teaspoon baking powder, and ½ teaspoon fine sea salt to the wet ingredients and mix just until combined. Use a spatula to scrape down the sides of the bowl.
- Line an 8" x 8" baking tin with parchment paper and press the cookie dough evenly into the bottom. Lightly flour your hands to prevent sticking. (If you're not baking right away, cover and refrigerate the dough for up to 3 days.)
- Bake the cookies for 15-18 minutes or until a toothpick inserted in the center comes out clean. The surface of the cookie bars will be a very light golden brown color.
- Take the tin out of the oven and transfer it to a wire cooling rack. Let the cookie bars cool down entirely in the tin before applying the frosting.
Make the Frosting
- Add 4 tablespoons (56 g) softened butter, 1 cup powdered sugar, and ½ teaspoon vanilla extract to a mixing bowl and beat with an electric mixer until smooth and creamy. If the frosting appears too thick, gradually incorporate up to 1 tablespoon heavy cream until the desired consistency is reached. If the frosting is too thin, mix in a few tablespoons of powdered sugar to thicken it.
- Spread the frosting over the cooled cookie and top with sprinkles. Lift the cookie out of the tin using the parchment paper and cut the cookie into 9 large or 18 small squares.
NOTES
- Measuring Ingredients: Our recipes are developed using a kitchen scale for precise measurements. Measuring cups can lead to inconsistent results, so keep that in mind if you’re not using a scale.
- Adjusting salt: We use Redmond's fine sea salt, which weighs 2 ½ grams per ½ teaspoon. If using regular table salt, use a heaping ¼ teaspoon. If using flaky sea salt, use ¾ teaspoon.
- Flour Substitutes: This recipe is designed for all-purpose flour, but you can substitute bread flour if needed. The texture may be slightly different.
- Discard Recipes: This recipe is designed to use leftover sourdough discard for added flavor and to reduce food waste. However, you can use an active starter if that's what you have on hand.
- Long Ferment: For a long ferment, this cookie dough can be pressed into the pan up to 3 days ahead of time and kept covered in the fridge until ready to bake.
- How to Store: To keep them fresh, store the squares in a covered container in the refrigerator for up to 5 days.
- How to Freeze: For longer storage, freeze the squares in a single layer on a baking sheet for 1 hour. Then transfer them to a freezer-safe container, placing parchment paper between layers. Store in the freezer for up to 1 month.
If I wanted to make these chocolate, could I replace some of the flour with cocoa powder?
Yes you can replace 2-3 tablespoons with cocoa powder.