Preheat the oven to 325 degrees F. Grease and line a metal 8×8 inch baking dish with parchment paper. Set aside.

Melt the butter in a medium-sized frying pan over medium heat, stirring occasionally. Once the butter is fully melted, it will begin to bubble. Continue to stir constantly until the bottom of the pan is covered with small amber specks (about 2–3 minutes). You should be left with 125g of browned butter.

170g (12 T) unsalted butter

If you are short on time, you can melt 125g of butter in the microwave with the sugar. Heat for 2 minutes total, stopping to stir every 30 seconds. Then continue with the recipe.

To a large bowl, add the sugar and sifted cocoa powder. Cocoa powder is notorious for having a bunch of lumps, so don’t skip the sifting!

300g (1 1/2 c) sugar, 75g (3/4 c) unsweetened cocoa powder, sifted

Carefully pour the browned butter into the large mixing bowl and whisk vigorously for 30 seconds.

Mixing the cocoa powder with the warm butter helps to “bloom” the cocoa, which gives these brownies a more decadent chocolate flavor. The warm butter also helps to dissolve the sugar, which will help to get that classic crinkle top!

Add the egg + 2 egg yolks, espresso powder (optional), vanilla extract and salt. Whisk until smooth.

1 egg, 2 egg yolks, .5g (1 tsp) espresso powder, 8g (2 tsp) vanilla extract, 5g (3/4 tsp) salt

With a rubber spatula, fold in the sourdough discard until there are no more white streaks.

120g (1/2 c) sourdough discard

You can use active starer, just make sure to use the same amount in grams.

Finally, fold in the flour and chocolate chips until the flour is just incorporated. Be careful not to over mix, as this can lead to a more cake-like brownie. You can also add or substitute with other inclusions. I also like to sprinkle the top with a few more chopped chocolate chunks

70g (1/2 c) all-purpose flour, 175g (1 c) chocolate chips/chunks

Scoop the brownie batter into the prepared baking dish and spread evenly with an offset spatula.

To long-ferment, cover the brownies with plastic wrap and store in the fridge overnight.

Bake the brownies for 35-40 minutes, or until just a few moist crumbs are on a toothpick that was inserted in the center.

For easy slicing, leave the Sourdough Brownies in the baking pan to cool until room temperature. Slice into 9 or 16 brownies and enjoy!