Sourdough Sugar Cookie Bars

A slice of sourdough sugar cookie bar topped with strawberry frosting and rainbow sprinkles displayed on a white plate. There is a bite taken out of the slice and two other pieces behind it stacked on top of each other.

Sourdough Sugar Cookie Bars

Delicious sourdough sugar cookie bars with a velvety texture and familiar sourdough tang from your starter! Topped with the best strawberry frosting around, you're going to love these cookie bars!

Course Dessert, Snack

Cuisine American

Keyword Sourdough Discard

Prep Time 20

Cook Time 30

Total Time 50

Servings bars

Calories 420kcal

Equipment

9" x 9" baking pan (also fits 8" x 12" for thinner bars)

Ingredients

260 g All Purpose Flour
3 g Baking Powder
4 g Cornstarch
2 g Salt
150 g Granulated Sugar
150 g Butter (softened, I've used salted)
1 Egg (extra large - if yours are small, use 2)
5 g Vanilla Extract (or almond extract or can add both)
100 g Sourdough Starter (or sourdough discard)

Frosting

80 g Butter (softened, I've used salted)
370 g Powdered Sugar
40 g Heavy Cream
5 g Vanilla Extract
4 g Salt
2 Strawberries (see notes)
20 g Sprinkles (optional, I've used rainbow sprinkles)

Instructions

Preheat the oven to 180C (350F) and line a 9" x 9" pan with parchment paper. Set this aside.
Add all purpose flour, baking powder, cornstarch and salt to a mixing bowl and whisk together until well combined. Set this aside.
Add the butter and sugar to a mixing bowl and cream them together using a hand mixer until they are light and creamy (you could also do this in a stand mixer if you prefer).
Add the egg, vanilla extract and sourdough starter to the butter and sugar mixture and beat on medium speed until well combined.
Now, add the wet mixture to the dry ingredient mixture and combine into a soft dough (use low speed on hand mixer or stand mixer or wooden spoon). Don't over mix the dough, it needs to just come together.
Place the mixture into your baking pan, lightly pressing down to ensure it is smoothed out to the edges.
Bake the sourdough sugar cookie bars for around 30 minutes or until the edges are lightly golden.
Remove from the oven and allow to cool in the pan completely. While the cookie bars are cooling, prepare the frosting.

Frosting

To the bowl of your stand mixer, add the butter, powdered sugar, heavy cream, salt and vanilla. Whisk on speed 3 to 4 until it comes together (it will be very stiff).
While the frosting is whisking, cut the strawberries up into small pieces and sprinkle a little powdered sugar over the top. Use a fork to mash it up so that it starts to liquefy. Once the juice has been released and it's fairly mashed up, it's ready to use!
Stop your stand mixer and swap over to the paddle attachment. Add the strawberries you just mashed up and whip the frosting until it's light and fluffy. I generally use speed 5 to 6 for this. It takes around 5 minutes for the frosting to be sufficiently whipped to perfection!
Once your sourdough cookie bars are cooled, top them with the pink frosting and sprinkles. Allow the frosting to set before slicing into bars.

Notes

VANILLA EXTRACT can be replaced with almond extract if you'd prefer.

BUTTER should be softened to room temperature - but don't let it start to melt. I've used salted butter like always.

SUGAR used in this recipe is fine white granulated sugar. You can use other sugars but they will alter the texture of the recipe.

MIXING INSTRUCTIONS FOR COOKIE DOUGH

You can mix this dough in a number of ways:

use an electric hand mixer (I find this the most convenient way to do it)
use a stand mixer (this way you can also bring the dough together in the stand mixer using the paddle attachment).
mix everything by hand (you'll need your muscles to cream the butter and sugar together).
use a Thermomix (speed 4 is fine to cream the butter and eggs, use dough mode to bring the dough together).

STRAWBERRIES FOR FROSTING - I've used 2 strawberries to color the frosting (and give it a hint of strawberry flavor). Frozen strawberries and raspberries work if you don't have a fresh strawberry. If you would prefer your frosting to be plain vanilla, you can leave the strawberries out altogether.

FERMENTING OVERNIGHT - You can ferment these sourdough sugar cookie bars overnight very easily! All you need to do is make the sugar cookie dough as per the instructions. When you get to step 6, instead of moving onto step 7 and placing into the oven, cover the dough in the pan and place into the fridge for up to 24 hours instead.

When you're ready to bake, preheat the oven and then place the cold dough straight from the fridge into the oven. Fermenting the dough and then placing it cold in the oven also helps to create a more chewy texture for these sourdough sugar cookie bars too!

Nutrition