Sourdough Peanut Butter Sandwich Cookies (Soft & Chewy)

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These soft and chewy sourdough peanut butter sandwich cookies are filled with a sweet peanut butter buttercream — the perfect from-scratch treat using sourdough discard.

There’s something deeply nostalgic about the smell of peanut butter cookies baking in the oven — and this sourdough version makes it even better. These soft and chewy sourdough peanut butter sandwich cookies are filled with a creamy peanut butter frosting, giving you a homemade twist on a childhood favorite using sourdough discard.

These soft and chewy sourdough peanut butter sandwich cookies bring that same familiar comfort but with a fun twist: they’re made with sourdough discard. If you’ve been baking sourdough bread for a while, you probably have a jar of discard sitting in your fridge waiting for a purpose. This recipe gives it one — and a delicious one at that.

These cookies are tender, perfectly chewy, and filled with a sweet, creamy peanut butter frosting. They’re everything you love about a classic peanut butter cookie recipe, but with the added depth of flavor that comes from using sourdough starter discard. Whether you’re a seasoned sourdough baker or just getting started, this is the perfect way to put that leftover starter to use in something sweet.

What You’ll Love About This Recipe

Simple and Delicious—Aside from being downright delicious, these cookies have a chewy texture that stays soft for days — especially when stored in an airtight container. The sourdough discard adds a subtle tang that balances the sweetness, creating layers of flavor you don’t usually get from a traditional peanut butter cookie. And when you sandwich that soft cookie around a swirl of creamy peanut butter buttercream, it’s just magic.
Simple Ingredients—This is one of those sourdough discard recipes that feels a little extra special without adding any extra work. The ingredients are simple, the steps are easy to follow, and the results are bakery-level good. Plus, there’s no fancy equipment required — just a large mixing bowl, a hand mixer or stand mixer with a paddle attachment, and a little patience while the cookies cool before filling.
Sourdough Discard—It’s also a great way to use up leftover sourdough discard if you’re in between bread bakes. Instead of tossing it, you’ll be rewarded with soft, chewy peanut butter cookies that taste like something out of a bakery case.

Key Ingredients

Here’s a quick look at what makes these cookies shine

Creamy peanut butter – For the best texture and flavor, use a no-stir variety (not natural peanut butter that separates). This helps the cookies stay soft and gives the filling its smooth, whipped consistency.
Brown sugar and granulated sugar – The combo gives the cookies their signature chewy texture. The brown sugar adds moisture and depth, while the white sugar helps them crisp just slightly around the edges.
Sourdough discard – This adds flavor and moisture to the dough. Even if your active starter isn’t bubbly enough to bake bread, it still works beautifully here.
All-purpose flour – This gives structure and stability, helping the cookie dough balls hold their shape as they bake.

You can find a full list of ingredients in the recipe card located at the bottom of this post.

How to Make Sourdough Peanut Butter Sandwich Cookies

You’ll start by making the cookie dough, followed by the peanut butter filling, then assemble the sandwiches. It’s simple, straightforward, and full of tons of amazing peanut butter flavor.

Cream the Butter and Sugars—In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with a hand mixer, cream together the unsalted butter, creamy peanut butter, brown sugar, and granulated sugar. Mix until the color lightens and the texture turns fluffy. This step is where the magic starts — aerating the butter creates that signature soft, chewy cookie texture.

Add Wet Ingredients—Mix in your sourdough discard, egg, and vanilla extract until everything is fully combined. Be sure your sourdough starter discard is at room temperature — cold discard can make the butter seize up and affect how well the ingredients come together. The discard adds a subtle tang that makes these cookies stand out among other peanut butter sourdough cookies.

Mix Dry Ingredients—In a separate bowl, whisk together your all-purpose flour, baking soda, baking powder, and salt. This ensures the leavening agents are evenly distributed and prevents clumping when mixed with the wet ingredients.

Slowly add the dry ingredients to the wet mixture, mixing just until combined. Avoid overmixing — that’s the key to keeping your cookies soft and tender instead of tough.

Chill the Dough (Optional but Recommended)—Cover the dough with plastic wrap and chill it in the fridge for about 30 minutes. This helps make shaping easier and enhances the texture of the cookies. The chilled dough also prevents spreading during baking, giving you the perfect chewy cookies every time.

Shape and Bake—Preheat your oven to 350°F. Line your baking tray or prepared baking sheet with parchment paper to prevent sticking and make cleanup easy.

Using a cookie scoop or a measuring cup, portion out about 1 to 1½ tablespoons of dough per cookie. Roll into small balls and lightly press down with a fork to create that classic criss-cross pattern on the top of each dough ball.

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Bake for 8–9 minutes — just until they’re golden brown around the edges but still soft in the center. If you prefer a firmer cookie, you can extend the baking time to 12–15 minutes, but I love pulling them out when they’re just set for that irresistible chewy texture.

Let the baked cookies cool on the baking tray for a few minutes before transferring to a wire rack or cooling rack to cool completely. Don’t rush this step — the cookies are delicate while warm and can break if handled too soon.

Make the Peanut Butter Filling—While the cookies cool, it’s time to whip up that luscious filling. In a large mixing bowl, beat together softened butter and creamy peanut butter until smooth and fluffy. Gradually add powdered sugar, mixing slowly at first, then increasing the speed as it comes together. Add vanilla extract, a pinch of salt, and a splash of cream or milk to reach your desired consistency.

Assemble the Sandwich Cookies—Once the cookies have cooled, pair them up by size. Pipe or spread a generous amount of the filling onto the flat side of one cookie, then top it with another. Press gently to create that perfect sandwich.

Chilling the assembled cookies for 5–10 minutes helps the filling firm up slightly, giving you that bakery-style bite when you sink your teeth in. The contrast between the soft cookies and creamy filling is pure perfection.

Baking Tips & Storage Suggestions

Tips & Storage Suggestions

For best results, always use room temperature butter and creamy peanut butter that’s not separated.
If your dough feels sticky, don’t be afraid to chill it a bit longer. Chilled dough is easier to work with and helps control spread.
Store cookies in an airtight container at room temperature for up to 3–4 days. For longer storage, refrigerate them and let them come to room temp before serving.
If you like experimenting, try adding mini chocolate chips to the filling or dipping half of each sandwich in melted chocolate — like peanut butter chocolate chip cookies or sourdough chocolate chip cookies in sandwich form.
These cookies also freeze beautifully. Just wrap them individually in plastic wrap and store them in a freezer-safe bag. When you’re ready for one, let it thaw for about 20 minutes — perfect with a cold glass of milk.

Recipe FAQs

Can I use active sourdough starter instead of discard?

Yes, but it will make the cookies puffier since active starter contains more yeast activity. I prefer discard for that dense, chewy bite.

Can I use natural peanut butter?

You can, but it changes the texture of the cookies. Natural peanut butter tends to separate, which can make the dough oily and crumbly. Stick with creamy peanut butter for the best sourdough peanut butter cookies.

What’s the bake time for smaller cookies?

If you use smaller scoops (about 1 tablespoon), reduce the bake time to around 7–8 minutes. Keep an eye on them — they should look golden brown and slightly soft in the center.

Do I have to make the filling?

Nope! These cookies are incredible on their own too — like chewy peanut butter cookies with a little tang from the discard. But the filling does take them to that next level of indulgence.

If you’re loving this recipe, try a few more of my favorites:

These sourdough cookie recipes are proof that sourdough isn’t just for bread — it can transform your favorite sweet recipes too!

A Final Thought

There’s something so simple yet special about slowing down to make a batch of cookies from scratch. Even more so when those cookies carry a piece of your sourdough journey in them. These sourdough discard peanut butter cookies are a reminder that not everything has to be complicated — sometimes it’s the little things, like baking a cookie and sharing it with your kids (or your amazing husband) that make a day feel full.

So next time you go to feed your sourdough starter, don’t toss that discard — turn it into something cozy, chewy, and full of love. These soft and chewy sourdough peanut butter sandwich cookies are the perfect way to use what you already have and create something truly delicious.

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If you make this recipe, please leave a rating on the recipe card below! I’d also love for you to tag me @autumn.chasingoursimple on Instagram so I can see what you’ve been baking!