Sourdough Discard S’Mores Cookies Recipe with Marshmallows

Homemade cookies with a twist—this Sourdough Discard S’Mores Cookies Recipe combines the tangy depth of sourdough discard with the classic flavors of graham crackers, chocolate, and gooey marshmallows. These cookies are a fantastic way to use extra sourdough starter or discard, reducing waste while creating a treat that tastes like a campfire classic.
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What you will Love about this Recipe!
- Zero Waste Baking – Put your sourdough discard to good use instead of tossing it.
- Classic S’Mores Flavor – Chocolate, graham crackers, and marshmallows in a chewy, tangy cookie.
- Make-Ahead Friendly – The dough can be chilled and baked when ready.
- Pantry Swaps Available – Use what you have to make these without an extra trip to the store.
- Homemade & Budget-Friendly – Skip expensive bakery cookies and make your own!
Equipment Needed to make Sourdough Discard S’Mores Cookies
- Mixing Bowls – This is for combining wet and dry ingredients.
- Hand Mixer, Kitchen Aid Stand Mixer or Bosch Mixer – Helps cream butter and sugar efficiently.
- Baking Sheets & Parchment Paper – This is for easy cleanup and even baking.
- Cookie Dough Scoop or Spoon – For uniform cookie sizes.
Ingredients Needed to Make Sourdough Discard S’Mores Cookies
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- ½ teaspoon salt
- ½ teaspoon cinnamon (optional, but adds depth)
- ½ cup graham cracker crumbs (Use homemade sourdough graham crackers)
- ¾ cup unsalted butter, softened
- ½ cup brown sugar
- 1 cup granulated sugar
- 1 cup sourdough discard (unfed)
- 1 egg
- 1 teaspoon vanilla extract (make your own)
Mix-Ins:
- ¾ cup semi-sweet chocolate chips or chopped Hershey’s chocolate bars
- ¾ cup mini marshmallows
- 3 graham crackers cut into pieces
Step-by-Step Guide to Make Sourdough Discard S’Mores Cookies
- Prep Your Ingredients – Preheat the oven to 350°F (175°C) and line a cookie sheet with parchment paper. Crush the graham crackers and measure out all the ingredients.
- Mix the Dry Ingredients – Whisk together flour, baking soda, salt, cinnamon (if using), and crushed graham crackers in a medium bowl. Set aside.
- Cream the Butter and Sugars – In a Kitchen Aid Stand Mixer, Bosch Mixer, or a large bowl, beat the butter, brown sugar, and granulated sugar with a mixer until light and fluffy (about 2 minutes).
- Add the Wet Ingredients – Mix in the sourdough discard, egg, and vanilla extract until smooth.
- Combine Wet and Dry – Gradually add the dry ingredients to the wet mixture, stirring until combined.
- Fold in Chocolate, Marshmallows and Graham Crackers – Using a rubber spatula, gently fold in the chocolate chips, mini marshmallows, and pieces of broken graham crackers, being careful not to overmix.
- Chill Dough – Chill dough in the refrigerator for a least 30 minutes.
- Scoop and Bake – Scoop cookie dough balls onto the lined baking sheets, leaving about 2 inches between each cookie. Bake for 10-12 minutes, or until the edges are crispy and the bottom of the cookie is golden brown.
- Cool and Enjoy! – Let cookies cool on the pan for 5 minutes before transferring to a wire cooling rack. Enjoy warm for the ultimate gooey marshmallow experience.

Storage and Serving Suggestions
- Storage: Keep cookies in an airtight container at room temperature for up to 4 days. For longer storage, freeze in a freezer-safe bag for up to 3 months.
- Serving: Enjoy these cookies with a cold glass of milk, a cup of coffee, or as a fun dessert for a backyard bonfire.
- Make It Extra Special: Warm a cookie in the microwave for 10 seconds before eating for a melty marshmallow effect.

Frequently Asked Questions:
1. Can I use sourdough discard straight from the fridge?
Yes! Unfed, cold discard works fine in this recipe—there is no need to bring it to room temperature.
2. What if I don’t have graham crackers?
You can swap them with crushed digestive biscuits or vanilla wafers for a similar texture and flavor.
3. Can I make these cookies dairy-free?
Yes! Use dairy-free butter and dairy-free chocolate chips to make these cookies completely dairy-free.
4. Why are my marshmallows disappearing into the cookies?
Marshmallows melt when baked, so try placing extra on top before baking to keep that gooey look.
5. Can I freeze the cookie dough?
Absolutely! Scoop the dough onto a baking sheet, freeze until solid, then transfer to a freezer bag. Bake straight from frozen, adding a couple of extra minutes to the baking time.
These Sourdough S’Mores Cookies are the perfect way to make the most of your discard while creating a delicious treat. With simple pantry swaps and make-ahead options, you’ll have a batch of cookies ready whenever a craving strikes. Happy baking!
Special Tools (affiliate links): Kitchen Aid Mixer | Bosch Mixer | Cookie Dough Scoop |
If you try this recipe and love it, please tag me on Instagram and Facebook @grindinggearsfarmstead.
Lechyd Da, (means “Cheers to Good Health” in Welsh)

Sourdough Discard S’Mores Cookie Recipe with Marshmallows
Ingredients
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- ½ teaspoon salt
- ½ teaspoon cinnamon optional
- ½ cup graham cracker crumbs Make your own
- ¾ cup unsalted butter softened
- ½ cup brown sugar
- 1 cup granulated sugar
- 1 cup sourdough discard unfed
- 1 egg
- 1 teaspoon vanilla extract Make your own
- ¾ cup semi-sweet chocolate chips or chopped Hershey’s chocolate bars
- ¾ cup mini marshmallows
- 3 graham crackers cut into pieces
Instructions
- Prep Your Ingredients – Preheat the oven to 350°F (175°C) and line a cookie sheet with parchment paper. Crush the graham crackers and measure out all the ingredients.
- Mix the Dry Ingredients – Whisk together flour, baking soda, salt, cinnamon (if using), and crushed graham crackers in a medium bowl. Set aside.
- Cream the Butter and Sugars – In a Kitchen Aid Stand Mixer, Bosch Mixer, or a large bowl, beat the butter, brown sugar, and granulated sugar with a mixer until light and fluffy (about 2 minutes).
- Add the Wet Ingredients – Mix in the sourdough discard, egg, and vanilla extract until smooth.
- Combine Wet and Dry – Gradually add the dry ingredients to the wet mixture, stirring until combined.
- Fold in Chocolate, Marshmallows and Graham Crackers – Using a rubber spatula, gently fold in the chocolate chips, mini marshmallows, and pieces of broken graham crackers, being careful not to overmix.
- Chill Dough – Chill dough in the refrigerator for a least 30 minutes.
- Scoop and Bake – Scoop cookie dough balls onto the lined baking sheets, leaving about 2 inches between each cookie. Bake for 10-12 minutes, or until the edges are crispy and the bottom of the cookie is golden brown.
- Cool and Enjoy! – Let cookies cool on the pan for 5 minutes before transferring to a wire cooling rack. Enjoy warm for the ultimate gooey marshmallow experience.