Sourdough Blueberry Lemon Bliss Bars

Name: Sourdough Blueberry Lemon Bliss Bars
Prep time: 30 min
Cook time: 28 min
Ingredients: 10 (140g) tbsp unsalted butter ( melted); ¾ (150g) cup brown sugar; ¼ (50g) cup granulated sugar; 2 large eggs (room temperature ); 1 egg yolk; ⅓ (80g) cup sourdough discard; 1 tsp vanilla extract; 1 tsp lemon extract; 2 tsp lemon zest (or one lemon ); 1½ (180g) cups all-purpose flour; ¾ tsp baking powder; 2 tsp cornstarch; ½ tsp salt; 1 (120g) cup blueberries (dried or fresh); 1 (150g) cup white chocolate chips; 8 (226g) oz full-fat cream cheese (softened); 2 (30g) tbsp unsalted butter (softened); 1½ (180g) cups powdered sugar; ½ tsp vanilla; ⅛ tsp salt; 1 tsp lemon extract; 2 tsp lemon zest (or one lemon); 1/2 (60g) cup blueberries (dried or fresh); 1/2 (85g) cup white chocolate chips; zest of one lemon

Jump to Recipe Print Recipe

If you love my Sourdough Cranberry Bliss Bars, then you’re going to be obsessed with this bright spring twist. These Sourdough Blueberry Lemon Bliss Bars are soft, chewy, and packed with sweet blueberries and fresh lemon flavor in every bite. The base is rich and buttery, then topped with a luscious lemon cream cheese frosting, a drizzle of white chocolate, and a pop of extra blueberries and lemon zest on top. They’re fresh, pretty, and the kind of bar that is perfect for spring.

Why You’ll Love This Recipe

Soft + chewy texture: These bars are perfectly chewy without being gummy.
Bright lemon flavor: Fresh citrus balances the sweetness of the blueberries.
Bursting with blueberries: these bars have little pockets of juicy blueberries in every bite, you can use fresh or dried!
A great way to use up discard: Have discard sitting in the frig? I got you. You can also let this blondie rest overnight in the frig for extra fermentation benefits!
Easy to make: this recipe is easy to whip up and easy to clean.

*As an amazon affiliate, this post may contain affiliate links which means I may receive a commission for qualifying purchases. I will only recommend products that I personally love and use.*

Tools You’ll Need:

9×13-inch baking pan- I love this pan from USA Bakeware linked here.
Parchment paper- to line pan to avoid burning and for a clean release. Don’t skip this!
Measuring cups and spoons– for measuring ingredients.
Mixing bowls- for batter and cream cheese frosting.
Whisk + spatula- to mix ingredients and spread batter and frosting.
Hand mixer- for whipping the frosting.
Digital scale (optional)- recommended for accurate measurements. I love this scale linked here.
Frosting knife (optional)- to spread icing.
Microplane or zester- for zesting lemons. I love this zester linked here.
Ziplock or pastry bag- for drizzling white chocolate.

Gather your Ingredients:

Unsalted butter– Adds richness and soft crumb texture to the blondie.
Eggs and egg yolk– Provides structure and helps bind the blondie.
Sourdough Discard– Adds flavor and moisture and is the magic that ferments your batter if desired. Can use starter/discard that is past peak or straight from the fridge.
White Granulated Sugar- Sweetens and helps give blondie that crackly top and crisp edge.
Brown Sugar– Adds sweetness and caramel notes to blondie.
Vanilla extract– Adds depth of flavor.
Cornstarch– helps to soften the crumb and prevent sinking in the center of the blondie.
All-purpose flour– Provides structure and lift to the batter. You can substitute bread flour but I like the softness all-purpose gives the blondie.
Baking powder– Helps with lift and rise without too much doming in the center.
Sea salt– Enhances overall flavor.
Lemon Extract- this is the key to getting a strong and bright citrus flavor in the blondies and the frosting without adding too much moisture. I like this lemon extract linked here.
Lemon Zest- this really helps bring out more lemon flavor in the blondie and the frosting.
Blueberries- any dried or fresh blueberries will work, but I prefer dried for a more consistent bake in the blondie. Don’t use frozen, they’ll release too much moisture.
White Chocolate- I like to use chips, but you could also use chunks depending on your preference.
Cream Cheese– Creates a creamy, tangy frosting we know and love to top the blondies.
Powdered Sugar– Sweetens and thickens the glaze. Do not use granulated sugar in the glaze or it will be grainy.

Instructions

Step 1: Mix the blondie base

Preheat the oven to 325°F. Line a 9×13-inch baking pan with parchment, leaving overhang. Don’t skip this step, it’ll make removing the bars so much easier.

In a microwave safe bowl or a small pot, melt your butter and whisk until smooth. Transfer to your mixing bowl.

Next add the brown sugar and white sugar to the butter, whisking to melt them together until the mixture is glossy.

Add the eggs, egg yolk, sourdough discard, vanilla, lemon zest, and lemon extract to the bowl and whisk until smooth.

Measure your flour, baking powder, cornstarch, and salt into the wet ingredients, and combine until the dry ingredients are just mixed in and streaks don’t remain. Don’t overmix at this stage, or the bars will be tough.

Fold in the blueberries and white chocolate into the blondie batter gently, then spread the batter into the prepared pan evenly.

Gently add the dry ingredients — Whisk the wet ingredients

Optional Overnight Fermentation: if you want to let this batter rest to have the sourdough discard work it’s magic, cover the blondie in the pan with plastic and transfer to the refrigerator overnight and bake the next day.

Bake the bar for 26-28 minutes, the edges should be browning and the center matte not shiny. You don’t want to overbake these or the centers will be dry! Internal temperature of the center when done should be 195 F.

Remove the pan from the oven as soon as the bar is done, and allow to cool completely before proceeding with frosting the bars.

Bars fresh out of the oven — Bars before baking

Step 2: Frost the bars

Make sure your cream cheese and butter are room temperature before mixing the frosting.

In a bowl, add the cream cheese and butter. Whip on high with hand beaters until smooth and light.

Add the vanilla, lemon extract, lemon zest, and salt to the frosting. Beat to mix in the ingredients for 30 seconds.

Lastly, add the powdered sugar to the frosting and combine on low to incorporate for a minute then increase the speed to high and whip the frosting for a minute until it’s fluffy and creamy.

Add remaining ingredients and whip — Cream the butter and cream cheese

In a microwave safe bowl, melt your white chocolate chips in 30 second intervals in the microwave until just melted. If needed, you can add a little coconut oil to thin the chocolate. Transfer the chocolate to a ziplock or pastry bag for later.

Spread the lemon cream cheese frosting evenly over your cooled bars, making sure to meet the edges.

Sprinkle more blueberries over the top of the bars.

Snipping off a small piece of the corner of your Ziplock or the pastry bag, drizzle the top of the bars in circular motions with the white chocolate. If you don’t have a pastry bag, you can also use a whisk to drizzle the chocolate.

Zest one lemon over the top of the bars for extra lemon flavor and color.

Garnish the bar with the frosting, white chocolate drizzle, and more blueberries and lemon zest

Transfer the bar to the refrigerator for about 1 hour to allow the icing and the white chocolate to set up.

After the icing has hardened, cut the bars into 12 even squares (4 rows across and 3 top to bottom). If you want them to look like the classic Bliss Bars, cut each of the squares in half to form rectangles.

Enjoy!

Yields 24 bars

How to Store:

Refrigeration- Store bars in an airtight container up to five days in the refrigerator. Because of the cream cheese frosting, these bars require to be refrigerated.

FAQ’S

Can I skip the lemon extract?

I don’t advise it. The lemon flavor will be very subtle if you do.

What is the difference between using fresh blueberries and dried?

Fresh blueberries can release more moisture and create more jammy pockets making the bars slightly softer. Dried blueberries make a more chewy and structured bar.

How do I know they’re done?

Edges should be set and the center slightly soft, they’ll finish as they cool.

If you enjoyed this recipe don’t forget to leave a comment and star review, and don’t forget to try more of my delicious sourdough blueberry lemon recipes!