Ingredients:
1 cup sourdough starter, unfed
3/4 cup unsalted butter, melted
1 cup brown sugar
1/2 cup granulated sugar
2 eggs
2 teaspoons vanilla extract
2 1/4 cups all-purpose flour
1 teaspoon baking soda
1/2 teaspoon salt
2 cups chocolate chips or chunks
1 cup walnuts, chopped (optional)
Directions:
Preheat your oven to 350°F (175°C) and line a 9×13 inch baking pan with parchment paper.
In a large bowl, combine the melted butter, brown sugar, and granulated sugar until well mixed.
Add the eggs and vanilla extract, mixing until fully incorporated.
Stir in the sourdough starter.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the chocolate chips and walnuts (if using).
Spread the batter evenly into the prepared baking pan.
Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean.
Let cool in the pan for 10 minutes before lifting out and cutting into bars.