Soft Sourdough Discard Chocolate Chip Cookie Bars

Imagine a pan of cookie bars emerging golden at the edges, the center plush and tender, chocolate freckling the surface like warm confetti.

Picture the buttery aroma mingling with a soft tang from sourdough, the first bite giving way to a fudgy, melt-in-your-mouth texture with just enough chew to satisfy.

I treasure recipes that turn kitchen “leftovers” into comfort, and sourdough discard transforms these bars into something both thrifty and luxurious.

They’re the kind of treat that makes Tuesday feel like a celebration—perfect for busy weeknights, potlucks, after-school cravings, or an easy dessert to tuck alongside Sunday suppers when you want homemade sweetness without fuss.

Last winter, these bars rescued me when friends popped by unexpectedly; I’d discard on hand, and in under an hour we were slicing warm squares that tasted like a bakery hug.

Ready? Let’s cook!

Why You’ll Love It

• Uses your sourdough discard—no waste, all flavor
• Delivers soft, gooey centers with chewy edges
• Mixes in one bowl with simple pantry staples
• Bakes quickly—no dough chilling required
• Freezes beautifully for make-ahead treats

Ingredients

• 113 g unsalted butter, melted and slightly cooled — keeps bars tender (use good European-style butter)
• 150 g light brown sugar, packed — adds moisture and caramel notes (choose fresh, soft sugar)
• 75 g granulated sugar — balances sweetness and spread (use fine white sugar)
• 1 large egg, room temperature — binds and enriches (select fresh, Grade A)
• 1 tsp vanilla extract — rounds out flavor (use pure extract)
• 150 g sourdough discard, 100% hydration — subtle tang and softness (use active-smelling discard)
• 190 g all-purpose flour — structure without toughness (unbleached if possible)
• 1/2 tsp baking soda — lift and tenderness (check freshness)
• 1/2 tsp fine sea salt — enhances flavors (avoid iodized)
• 170 g semi-sweet chocolate chips — melty pockets (choose 50–60% cacao)
• 60 g chopped walnuts, optional — toasty crunch (lightly toast for best flavor)

Step-by-Step Method

Preheat & Prep the Pan

Preheat oven to 350°F (175°C). Line a 9×9-inch pan with parchment, leaving a 1-2 inch overhang on two sides for easy lifting. Lightly grease the exposed sides. Gather tools and ingredients. Make sure the egg is room temperature and the melted butter is slightly cooled to avoid greasiness and promote an even, tender crumb.

Whisk the Sugars with Butter

Whisk melted, slightly cooled butter with packed brown sugar and granulated sugar until glossy and cohesive, about 30 to 45 seconds. Break up any sugar lumps. Aim for a smooth mixture with a light sheen. Proper emulsification here sets the foundation for chewy edges and a soft, moist center in the finished bars.

Add Egg, Vanilla & Discard

Whisk in the egg and vanilla until smooth and slightly thickened. Stir in the sourdough discard until fully incorporated with no streaks. Keep the mixture uniform. If discard seems very runny, remember you can add a bit more flour later. This step builds structure while keeping the batter plush and flavorful.

Combine Dry Ingredients

In a separate bowl, whisk the flour, baking soda, and fine sea salt until evenly distributed. Break up any flour pockets. Properly combining these dry ingredients ensures even leavening and seasoning. Set the bowl aside, ready to fold into the wet mixture without overworking the batter, which preserves tenderness.

Fold Wet & Dry Together

Switch to a rubber spatula. Gently fold the dry mixture into the wet until just combined and no dry streaks remain. Scrape the bowl edges and bottom to catch hidden flour. Stop as soon as the batter looks uniform. Overmixing can develop gluten, resulting in tougher bars rather than soft, tender ones.

Stir in Chips & Nuts

Fold in the chocolate chips and chopped walnuts, if using, reserving a small handful of chips for topping. Distribute mix-ins evenly without overworking the batter. For varied texture, swap some chips for chopped chocolate. Keep the batter cohesive and thick, ensuring every bite has chocolate and nutty crunch.

Spread, Smooth & Top

Scrape the batter into the prepared pan. Spread evenly to the corners and smooth the surface with a spatula. Sprinkle reserved chocolate chips over the top for a bakery-style finish. Slightly press them in so they adhere. Even thickness promotes uniform baking and attractive, consistent bar sizes.

Bake to Doneness

Bake 20 to 24 minutes until edges are set and lightly golden. The center should look just set, and a toothpick inserted should come out with a few moist crumbs. For chewier edges, go closer to 24 minutes; for softer centers, pull at 20 to 21. Avoid overbaking to keep bars soft.

Cool, Lift & Slice

Cool the pan on a wire rack for 20 minutes. Use the parchment overhang to lift the slab out in one piece. Transfer to the rack and cool slightly more if needed. Slice into 16 bars with a sharp knife, wiping between cuts for clean edges. Optionally finish with flaky salt for balance.

Ingredient Swaps

• Dairy-free: use vegan butter or refined coconut oil; make certain chocolate chips are dairy-free.
• Egg-free: replace 1 egg with 60 g unsweetened applesauce, 1 flax egg (1 tbsp ground flax + 3 tbsp water), or 3 tbsp aquafaba.
• Gluten-free: swap AP flour for a 1:1 gluten-free baking blend; use gluten-free sourdough discard.
• Nut-free: omit walnuts or use seeds (pumpkin/sunflower).
• Budget/Regional: replace some chips with chopped bar chocolate; use dark or milk chocolate available; light brown sugar can be made by mixing 150 g granulated sugar with 1 tbsp molasses.

You Must Know

Doneness • If the center looks set but you want gooier bars, pull when the top is pale-golden and the toothpick shows glossy streaks with 3–5 moist crumbs at 20–21 minutes; carryover heat will finish the edges in the pan.

Troubleshoot • If the batter feels loose or “slippy” after adding discard, stir in 10–15 g flour until it ribbons off the spatula in thick sheets; too runny batter bakes up flat and greasy.

Avoid • Avoid cutting hot; wait at least 20 minutes on a rack and slice when the slab is just warm to the touch (about 95–105°F center) to prevent crumbling and smeared chocolate.

Scale • For a 9×13-inch pan, multiply all ingredients by 1.5 (e.g., flour 190 g → 285 g; butter 113 g → 170 g), spread to even thickness, and start checking doneness at 22 minutes; expect 24–28 minutes total.

Flavor Boost • For deeper butterscotch notes, brown the butter to medium amber and cool to 90–95°F before proceeding; add 1/4 tsp espresso powder to the sugars to enhance chocolate without tasting like coffee.

Serving Tips

• Serve slightly warm with vanilla ice cream and a drizzle of salted caramel.
• Plate with fresh berries and a dusting of powdered sugar for contrast.
• Add a sprinkle of flaky sea salt and shaved dark chocolate on top.
• Pair with cold brew coffee or a glass of cold milk.
• Cut into bite-size squares and skewer with cocktail picks for parties.

Storage & Make-Ahead

Store cookie bars airtight at room temperature 2–3 days or in the fridge up to 1 week.

Bring to room temperature before serving for best texture.

For make-ahead, bake, cool, and slice.

Alternatively, freeze unbaked dough pressed into the pan.

Baked bars freeze up to 2 months.

Thaw and warm lightly.

Reheating

Reheat gently: microwave 10–15 seconds per bar, loosely covered.

Oven at 300°F for 6–8 minutes, tented with foil.

Stovetop: warm in covered skillet on low 2–3 minutes, flipping once.

Bake-Sale Staple Status

Often the first tray to empty, these sourdough chocolate chip cookie bars bring bakery-level aroma and crowd-pleasing chew to any bake sale.

I cut them into tidy squares, edges caramel-gold and centers tender, and watch a line form as the chocolate freckles glisten.

The sourdough discard lends a whisper of tang that brightens the sweetness, so every bite tastes balanced and memorable.

They travel well, slice cleanly, and sell even faster with a small hand-lettered sign.

1. Familiar comfort, slight twist: the sourdough note nudges nostalgia into something new, inviting curious tasters and loyal regulars alike.
2. Batch-friendly reliability: 9×9 pans turn out uniform bars that stack neatly and price easily.
3. Aroma as advertisement: warm butter and vanilla float across the room, guiding wallets toward your table.

Final Thoughts

Give these sourdough chocolate chip cookie bars a try—you’ll love the soft, gooey centers and toasty edges.

Feel free to tweak them with your favorite mix-ins, a sprinkle of flaky salt, or extra chocolate on top!

Frequently Asked Questions

Can I Make These Gluten-Free With a Specific Flour Blend?

Yes—you can. I recommend a 1:1 gluten-free baking blend with xanthan gum. I’d swap cup-for-cup, rest the batter 10 minutes, and bake toward the longer time. Expect tender, chewy edges and cozy, chocolatey warmth.

How Do High-Altitude Adjustments Change Bake Time or Leavening?

At altitude, I bake 2–4 minutes less, watch for moist crumbs, reduce baking soda to 1/4 teaspoon, add 1–2 tablespoons flour, and bump moisture slightly. I’ll cue you: golden edges, fragrant center, gentle puff—pull them.

What Mixer Speed or Hand-Mixing Method Yields Best Texture?

Use low speed or a gentle whisk: I mix sugars and butter until glossy, then whisk egg and vanilla briefly. I fold flour by hand with a spatula, slow, sweeping strokes—just combined—preserving tender, plush crumbs.

Are Pasteurized Eggs Necessary for Safety in Underbaked Centers?

Yes—use pasteurized eggs if you’ll enjoy gooey, underbaked centers. I picture warm, fudgy squares and your peace of mind. I choose pasteurized eggs, bake gently, and savor without worry; they keep the indulgence safe, cozy, and carefree.

How Do I Scale the Recipe for a Half or Double Batch?

Scale straight: for half, use a 8×4.5-inch or 8-inch round, bake 16–20 minutes; for double, use 9×13, bake 24–28 minutes. I’d halve or double every ingredient precisely; keep discard hydration consistent.