Sourdough Discard (1/2 cup, 120g): This is the star of the show. Your discard should ideally be unfed and at room temperature. It acts as both a binding agent and a flavor enhancer, imparting a subtle tang that perfectly offsets the sweetness of the chocolate.Unsalted Butter (1 cup, 226g): We will be browning this butter. The Maillard reaction creates an intoxicating, nutty aroma that pairs beautifully with the sourdough tang.Dark Brown Sugar (1 cup, 200g): Packed tightly! Brown sugar contains molasses, which adds moisture, chewiness, and deep caramel undertones to the dough.Granulated White Sugar (1/2 cup, 100g): Essential for providing the crisp, caramelized edges we all crave.Large Egg + 1 Egg Yolk: The extra yolk provides additional fat, ensuring the final bake remains tender rather than cakey.Pure Vanilla Extract (1 tablespoon): Do not skimp on this. Vanilla acts as the flavor bridge between the butter, chocolate, and sourdough discard.Bread Flour (1 ½ cups, 180g) & All-Purpose Flour (1 cup, 120g): The higher protein content in bread flour encourages gluten development for a chewier texture, while all-purpose flour keeps the crumb perfectly tender.Baking Soda (1 teaspoon): The primary leavening agent that reacts with the acidity of the sourdough to create a beautiful lift.Fine Sea Salt (1 teaspoon): Crucial for balancing the profound sweetness.Semi-Sweet Chocolate Chunks (2 cups): High-quality chocolate chunks will melt into glorious, gooey pools.