Sourdough frosted fudge brownies

This is another fabulous recipe that utilizes your sourdough discard. These sourdough frosted fudge brownies are slightly tangy and perfect to share with friends and family!

sourdough frosted brownies

In case you haven’t noticed, I don’t like throwing things away. In fact, I have many items in my possession from my childhood. You know, things like Care Bears, Cabbage Patch Kids and even mechanical pencils and Post-It notes. What can I say? They’re sentimental, and you never know when you might be able to use them. I’ve given most of these things to my dear Addie, but some things I still use today (see: my collection of stationery).

The same thing goes with food. If I have extra or something, I don’t want to throw it away. In my mind, it’s a waste of food. One of the main things about sourdough that scared me initially was having to discard part of it. Thankfully, I’ve come across many recipes that utilize sourdough starter so I don’t waste ingredients. After all, I did a lot of this sourdough baking during height of the pandemic where flour and other baking supplies were scarce.

sourdough frosted brownies

One sunny morning, I was in the midst of baking some sourdough bread. However, I couldn’t just stop there. I knew that I wanted to try something else before I put my dear Pumbaa (the name of my sourdough starter) back in the refrigerator to rest. Since I am a chocoholic, I decided on brownies. That’s where this recipe came in.

Yes, this recipe makes a large pan. But it’s a great excuse to give some away to essential workers, friends or family. I decided to frost mine with a chocolate frosting because that’s how I roll. If you prefer to keep the brownies plain so you can experience the slight tangy-ness from the sourdough, be my guest.

sourdough frosted brownies

My husband gave these a 5. I downgraded my rating slightly because I didn’t like how crumbly they were (but the crumbs were not dry). Addie said the sourdough flavor was too pronounced – but then again, she’s a kid and doesn’t appreciate sourdough quite yet.

Husband’s rating: 5 out of 5
Addie’s rating: 3 out of 5
My rating: 4 out of 5

Sourdough frosted fudge brownies

Don't throw away your sourdough discard! Instead, make these frosted fudge brownies!
Prep Time25 minutes
Cook Time25 minutes
Total Time50 minutes
Course: Dessert
Cuisine: Asian
Keyword: Bars
Servings: 24
Author: Eva Bakes



  • 9 ounces (252 grams) bittersweet chocolate chopped finely
  • 2 sticks (224 grams) unsalted butter cut into chunks
  • 1 cup (224 grams) granulated sugar
  • ½ cup (112 grams) brown sugar packed
  • ½ teaspoon salt
  • 1 Tablespoon vanilla extract
  • 3 large eggs
  • 1 cup (224 grams) sourdough starter 100% hydration
  • ½ cup (70 grams) all-purpose flour


  • 1 stick unsalted butter room temperature
  • 1 cup unsweetened cocoa powder
  • 2 cups powdered sugar
  • 2-3 Tablespoons milk of choice
  • pinch salt
  • 1 teaspoon vanilla extract


Bake the brownies

  • Preheat your oven to 350°F. Generously grease or line a 9"x13" baking pan and set aside.
  • In a large microwave-safe bowl, add the chopped chocolate and butter. Microwave on high for 1 minute and stir well. Microwave another 30 seconds or so until the butter and chocolate are completely melted. Stir well.
  • Add the sugars, salt and vanilla and mix until well incorporated. Then add the eggs and mix vigorously until you no longer see any traces of the egg (about 30 seconds).
  • Gently fold in the sourdough discard and mix. Then add the flour and mix until everything just comes together.
  • Transfer the batter to your prepared baking pan (be sure to smooth out the top) and bake in your preheated oven for 25 minutes or until a toothpick inserted in the center comes out with some wet crumbs.
  • Allow the brownies to cool completely before frosting.

Make the frosting

  • In the bowl of a stand mixer fitted with the paddle attachment or in a large bowl if using a handheld mixer, cream the butter with the cocoa powder on medium speed until light and fluffy, about 2-3 minutes.
  • Turn the mixer to low and slowly add in the powdered sugar. Then stream in the milk. Add the salt and vanilla and continue to mix. If the frosting is too thick, add more milk. If it's too runny, add more powdered sugar.
  • Once the frosting is to your liking, spread it on top of the cooled brownies. Slice and enjoy.


Leftover brownies should be stored in an airtight container at room temperature or in the refrigerator and will keep for several days.
Source: Brownies from Baking Sense; frosting is an Eva Bakes original

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