makes one 9 x 13–inch pan 
If you have any sourdough skeptics in your life, you can easily convert them with these brownies. It may seem like an unlikely combo at first glance, but sourdough and chocolate go together like peanut butter and jelly. The richness of the chocolate plays beautifully with the tanginess of the sourdough, making these brownies a sweet way to keep excess starter from (literally) going down the drain.
½ cups packed brown sugar, preferably organic whole cane sugar
1¼ cups coconut oil, melted
3 large eggs
1½ cups sourdough starter (here)
2 teaspoons vanilla extract
½ cup all-purpose flour
½ cup cocoa powder
½ teaspoon fine sea salt
1 cup chocolate chips
Preheat the oven to 375°F. Grease a 9 x 13–inch pan.
In a large bowl, combine the sugar and oil, then mix in the eggs, sourdough starter, and vanilla.
In a separate bowl, mix together the flour, cocoa powder, and salt and add to the wet ingredients, stirring until just combined.
Pour the batter into the prepared pan. Bake for 20 to 25 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven and immediately sprinkle with the chocolate chips and let them sit for a few minutes to soften before spreading them evenly across the top of the brownies.
Cool for 30 minutes, then transfer them to the freezer for 1 hour. Let the brownies sit at room temperature for 20 minutes and slice before serving. Store tightly covered at room temperature for up to 2 days.
kitchen notes • Either semisweet or milk chocolate chips will work for these brownies. And of course, the chocolate chip layer is optional, but really … who wants to omit chocolate chips?
The freezer step might sound strange, but it has a magical way of making brownies extra fudgy. Trust me. Skip it at your own risk.