Gooey with a crackly top, and decadent brown sugar flavor, these sourdough blondies are out of this world. The flavor of sourdough adds a much-needed complexity that tames and perfectly complements the sweetness of this sugary treat.
These sourdough blondies are a revelation. I am so glad I finally had an excuse to make these because they turned out incredible and are so easy to make. The best part is that everything can be mixed in 1 bowl.
Warning: Mini Rant
Be forewarned these have a ton of sugar and butter! But that’s what makes them so delicious. I don’t frequently make healthy versions of desserts and most of the recipes you’ll find in my blog are full fat and full sugar, like my Chewy Discard Oatmeal Cookies and Pineapple Upside Down Cake recipes.
Truth be told, I’ve struggled with body image issues for most of my life, and as I enter my 30s I’m trying to normalize my relationship with food. I won’t even call these an indulgence or a treat, and I don’t recommend that you eat these on your “cheat” day. After 3 decades of living on this earth, I 0realize that “healthy” or diet versions of desserts just don’t cut it for me and I always end up satiating my cravings by eating other unhealthy foods whenever I don’t eat the “real” thing. So if I want a blondie...I’m eating a blondie! Not because I “deserve” it for running a mile or eating well all week.
Today, my personal journey is to stop seeing food as a reward for good behavior, and letting myself eat the things I want without beating myself up about it.
TLDR: These blondies are not healthy, and they contain ingredients that may or may not be bad for you. If you decide to use less butter or sugar, I look forward to hearing about your results, but I can’t guarantee the outcome.
What you need
Ingredients
- Butter - Imparts richness and creates a light and tender texture.
- Brown sugar - Adds a lovely molasses flavor.
- Granulated sugar - Adds sweetness and structure.
- Egg yolks - Adds richness.
- Sourdough discard - Adds a delicious tangy flavor and moisture so these blondies taste fresher for longer.
- All-purpose flour - The low protein content of all-purpose flour imparts softness.
- Baking powder - The main leavening agent for these blondies, adds lightness and prevents your blondies from being too dense.
- Kosher salt - Brings out the flavor of all the other ingredients in these blondies.
- Spiced Rum - Adds a rich vanilla flavor. You can substitute with any other dark liquor or 7 grams of vanilla.
- Chocolate Chips and Pecans - Adds texture. Feel free to substitute with your mix-ins of choice. See options my favorites below.
Equipment
- Mixing bowls
- Parchment paper
- Baking pan
- Spatula
- Mesh strainer
- Off-set spatula
- Cooling rack
My Favorite Mix-in Combinations
These blondies are super versatile and are great with different mix-ins. So get creative! I’ve found the sweet spot is adding a total of 200 grams of a mix of nuts, chocolate chips and dried fruits, this way you’ll still get tons of ooey gooey blondie texture in every bite without the other ingredients taking over.
- Semi Sweet Chocolate Chips and Pecans (what I use in this recipe)
- Dark and White Chocolate Chips, Walnuts and Coconut Flakes
- Milk Chocolate Chips and Hazelnuts
- White Chocolates and Dried Apricots
How to bake your blondies
- Preheat your oven and line a baking pan with parchment paper
- Combine melted butter and sugars
- Add egg yolks, sourdough discard and rum until no traces of discard and egg remains
- Stir until the mixture is lighter in color
- Sift and fold the all-purpose flour, baking powder and salt into the butter mixture
- Pour batter into baking pan
You can bake these in an 8-inch or 9 by 13-inch baking pan depending on how thick you want your blondies. I’ve found that you can achieve the gooey texture either way.
- Bake for 25 to 30 minutes
Watch your blondies and cut a few minutes from the baking time if you’re baking in a larger pan. Don’t over bake or they may be too tough and dry.

Sourdough Discard Blondies
Ingredients
Batter
- 170 grams 12 tablespoons Unsalted Butter (melted and slightly cooled)
- 200 grams 1 cup Brown Sugar
- 150 grams ¾ cup Granulated Sugar
- 2 Egg Yolks
- 120 grams ½ cup Sourdough Discard
- 190 grams 1 ⅔ cup All-purpose Flour
- 5 grams 1 teaspoon Baking Powder
- 4 grams ¾ teaspoon Kosher Salt
- 15 grams 1 tablespoon Rum, Whiskey or Bourbon (optional)
Mix-ins
- 100 grams ⅔ cup chocolate chips
- 100 grams 1 cup pecan pieces
Instructions
- Prep: Preheat your oven to 350 F (176 C). Line an 8-inch baking pan with parchment paper.
- Make the batter: In a large mixing bowl, stir together melted butter and sugars until well combined. Add in egg yolks, starter and rum, if using. Stir until all of the ingredients are combined, your mixture will lighten in color. Sift and stir in flour, baking powder and salt into the butter mixture. Fold mix-ins into the batter.
- Scoop the batter into the pan and spread into an even layer. The batter will be very thick, but be sure that you get it into the corners.
- Bake: Bake the blondies for 25 to 30 minutes or until the top looks set and crackly. Allow the blondies to cool in the pan for 10 minutes, remove to a wire rack and allow to cool completely before slicing and serving.
Notes

Wendy says
These are as good as you say they are. I did use butterscotch chips and added a little extra dark rum and wow! people have loved them. Thankyou!
Make It Dough says
So happy you liked them!
Carly says
Every time I make these they require a lot more time in the oven and still don't seem fully cooked. What do you suggest I do to get fluffy like they look in the picture?
Make It Dough says
Oh no! Sorry to hear that. You could try increasing the temperature a little bit. This bake is very forgiving! Try that and let us know how it goes.
Vera says
Every time I make this, it’s so crumbly and fragile, what do you suggest ? Thank you
Make It Dough says
You may be slightly over baking the blondies! Try not baking them for as long as you have.
Vera says
Thank you for your reply… I was using my convection oven 170 C for 25 minutes, still confused 🤔
Make It Dough says
Please keep in my mind that everyone's oven is different. Mine is not super accurate and has a tendency to run colder than others, so yours may just get a little hotter than mine does. All of these recipes are tested by me in my home kitchen, which may be different from yours so you'll have to tailor these recipes to make them work in your home. Try baking them for 18 to 20 minutes instead of 25 like you said and let us know if that works!