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Sourdough Cookie Bars

4.86 from 14 votes
Elien Lewis
These sourdough cookie bars are thick and chewy made with browned butter and lots of chocolate. They taste like chocolate chip cookies but you can skip the individual rolling!
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A close-up of gooey sourdough cookie bars with melted chocolate in the center, resting on a wire cooling rack.
Prep Time 20 minutes
Cook Time 30 minutes
2 hours
Total Time 2 hours 50 minutes
Servings 16

Ingredients
 
 

  • 140 g unsalted butter
  • 100 g soft brown sugar
  • 100 g granulated sugar
  • 100 g discard sourdough starter
  • 1 large egg
  • 1 teaspoon vanilla extract
  • 3/4 teaspoon baking soda
  • ½ teaspoon salt
  • 190 g all-purpose flour
  • 170 g semi-sweet chocolate chips
  • Flaky salt to serve

Instructions
 

  • Let the butter melt in a saucepan. Once melted, let it cook further for around 3-4 minutes, stirring occasionally until the milk solids have caramelized and the butter smells nutty. 140 g unsalted butter
  • Pour the browned butter and all the browned bits, into a large heat-proof bowl. Allow it to cool at room temperature for about 10 minutes, then refrigerate until solidified, but you can still press a finger into it. ** It will be about 112-115g of browned butter.
  • Once the brown butter has solidified, add the brown sugar, granulated sugar and cream with an electric mixer for around 2 minutes until light and fluffy. 100 g soft brown sugar, 100 g granulated sugar
  • Next, mix in the sourdough starter, egg, and vanilla and mix well. Stir in the baking soda and salt until well combined. 100 g discard sourdough starter, 1 large egg, 1 teaspoon vanilla extract, 3/4 teaspoon baking soda, ½ teaspoon salt
  • Add the flour and mix until almost combined, with a few dry streaks remaining. Add the chocolate chips and stir to combine. 190 g all-purpose flour, 170 g semi-sweet chocolate chips
  • Preheat the oven to 350°F (180°C). Line a 8x8-inch (20x20cm) baking pan with parchment paper.
  • Scoop the cookie dough into the lined pan. Smooth it out with the back of a spoon or offset spatula
  • Bake it right away, or cover and chill in the fridge for up to 3 days.
  • Bake the cookie bars for around 25-28 minutes until the top is set and golden brown.
  • Let the cookie bar cool in the tin for an hour before removing and letting it cool completely on a wire rack. The cookies will be pretty soft while still warm but will firm up as they cool to room temperature.
  • To serve, slice the cookies into individual cookies with a sharp knife. Slice four rows horizontally and four rows vertically to create 16 pieces.

Notes

**Recipe Update Note:
I’ve slightly changed the method for browning the butter to ensure these cookie bars bake up perfectly without being oily. Instead of mixing melted browned butter directly into the dough, you now chill the browned butter first until it’s solid but still soft enough to cream smoothly with sugar.
Original browned butter method:
Let the butter melt in a saucepan, cooking for around 3–4 minutes until milk solids caramelize and butter smells nutty. Pour melted browned butter into a heat-proof bowl, cool for about 10 minutes, then mix directly with sugars, starter, egg vanilla,  and remaining ingredients as outlined in the main recipe. Chill the dough for at least 2 hours before baking.
 
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Nutrition

Calories: 225kcalCarbohydrates: 28gProtein: 3gFat: 12gSaturated Fat: 7gPolyunsaturated Fat: 1gMonounsaturated Fat: 3gTrans Fat: 0.3gCholesterol: 31mgSodium: 133mgPotassium: 88mgFiber: 1gSugar: 16gVitamin A: 241IUCalcium: 18mgIron: 1mg
Keyword brown butter, cookie bars, Sourdough
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