Gluten Free Sourdough Oatmeal Cookies (Sourdough Discard Recipe)

Gluten Free Sourdough Oatmeal Cookies are a delicious twist on the classic treat, combining the rich flavor of brown butter with a little tang from the sourdough discard. The chewy oats give them a perfect texture, while the sourdough adds a little extra depth. Whether you add chocolate chips, dried fruit, or butterscotch, these sourdough discard oatmeal cookies are sure are a delicious way to use up any gluten free sourdough discard you may have on hand.

Recipe Ingredient Notes

Gluten Free Flour: I tested this gluten free sourdough oatmeal cookie recipe with both King Arthur Measure for Measure and Bob’s Red Mill 1-to-1. Both flour blends worked well. The cookies made with King Arthur spread less and had a more compact texture compared to those made with Bob’s Red Mill.  I have not tested this recipe with my own gluten-free flour blend but it should work great in this application. The baking flours mentioned do contain xanthan gum.

Sourdough Discard: I use a 100% hydration sourdough starter meaning I use equal parts of gluten free super fine brown rice flour and water. Sourdough discard refers to a portion of the gluten free sourdough starter that is removed and discarded during the feeding process. You can use a fed or unfeed gluten-free sourdough starter in this recipe for sourdough oatmeal cookies. I prefer using room temperature discard. But if you have your discard stored in the fridge, it works just as well. The sourdough discard adds delicious flavor to the cookies and pairs very well with the brown butter. Make sure the sourdough discard comes from a starter that is at least 7 days old (or older and more established) but the discard itself should not be older than 2-3 days or it would be too sour. And no worries, the cookies will not taste sour from the discard.

Milk Powder: Adding whole or non-fat milk powder enhances the brown butter's richness and nuttiness. While optional, it's worth considering if you're a fan of brown butter. Be sure to use dairy milk powder—non-dairy alternatives like coconut milk powder won’t work.

Gluten Free Oats: For the best results, make sure to use Old-Fashioned Oats (rolled oats) in this recipe. Unlike quick oats, which are rolled too thin, old-fashioned oats retain their hearty texture, giving the cookies their signature chewiness.

Egg Yolk: Make sure to use only the egg yolk. The water found in the sourdough discard replaces some of the egg white.

How to make Brown Butter

Beurre noisette, also known as brown butter, is made by cooking butter past its melting point until the milk solids separate and caramelize. This process imparts a rich, nutty flavor and a deep golden-brown color. The caramelized milk solids enhance the butter’s taste, giving it a warm, slightly sweet, and toasty profile.

If you've never made brown butter before, take your time and use low to medium heat for better control. A heavy-bottomed, light-colored saucepan (such as white enamel) makes it easier to monitor the color of the milk solids. Use a heat-proof spatula or wooden spoon for stirring.

1. Place unsalted butter (cold or frozen) in a heavy-bottomed saucepan. If you have a pan with a white enamel interior, use it to better see the milk solids as they caramelize.
2. Melt the butter over medium heat. Once fully melted, stir in the additional milk powder if using. The butter will become foamy, then transition to a rapid bubble. Stir continuously, making sure to scrape the bottom of the pan to prevent burning.
3. Continue cooking and stirring until the butter smells nutty and turns a medium amber color. Brown specks (caramelized milk solids) will appear at the bottom of the pan, and the aroma will become rich and toasty. Be careful - brown butter can burn quickly at this stage.
4. Immediately remove from heat and pour into the bowl of a stand mixer or a heat-proof container, making sure to include all the browned bits. Let it cool for about 15 minutes before using. For this gluten free sourdough oatmeal cookie recipe, the butter should be cool but still liquid.

Sourdough Oatmeal Cookie Dough

The dough for sourdough discard oatmeal cookies can be made by hand with a whisk but you may also use a hand mixer or your stand mixer. This recipe was developed to use both, brown butter and sourdough discard. With this being said both ingredients are required for the recipe to work correctly.

1. Start by browning the unsalted butter in a small pot, transfer it to a large bowl, and allow the butter to cool to room temperature. Make sure to scrape all the brown bits and pieces from the pot you browned the butter in. Allow the brown butter to cool for 15 minutes.
2. In a separate bowl, whisk together the gluten-free flour, baking soda, cinnamon, and kosher salt. Set aside.
3. Add the brown sugar and granulated sugar to the cooled brown butter, whisking until smooth.
4. Next, add the room-temperature egg yolk, vanilla extract, and sourdough discard to the butter-sugar mixture. Whisk until fully combined and the mixture is smooth and slightly thickened.
5. Gently fold the dry ingredients into the wet ingredients until just a few streaks of flour remain. Finally add the gluten free oats and fold until evenly incorporated. If you would like to add some add-ins like chocolate chips you can add them along with the old fashioned rolled oats.
6. Place the sourdough cookie dough in your fridge for 20 minutes to allow the butter to set up and the flour and oats to hydrate. You can let the cookie dough chill for a longer period but keep in mind the cookies may not spread as well.

Baking Instructions

1. When ready to bake, preheat your oven to 350F. Arrange your oven racks in the middle.
2. Line a large baking sheet with parchment paper and use a 2 Tablespoon Cookie Scoop (I refer to this as the #20 - yellow scoop) and portion out the oatmeal cookie dough. You should get 9-10 cookies out of this dough, depending on how much dough you snacked on. Please be aware the longer the cookie dough is in the fridge, the harder it may be to scoop the dough.
3. Gently flatten each cookie dough ball , shaping it more like a hockey puck than a round ball. I aim for them to be around ½" thick.
4. When your oven is fully preheated, arrange 6 cookies on the parchment lined cookie sheet. Bake them at 350F for 10-11 minutes.
5. The oatmeal cookies should appear puffy and start to get golden brown on the edges. These cookies are meant to be chewy and soft, so be careful not to overbake them. You want the cookies slightly underdone since they will continue to set as they cool. (Keep in mind baking times can vary from oven to oven and the size of the cookie dough)
6. Remove from the oven and with a round cookie cutter slightly larger than the cookie to scoot them into a perfectly round shape. You can also use a glass to do this if you don't have a round cookie cutter.
7. Allow the cookie to cool for 5-10 minutes on the baking pan before moving to a wire rack to cool completely.
8. Repeat with the remaining sourdough discard oatmeal cookie dough.

Storage & Freezing

While these Gluten Free Sourdough Oatmeal Cookies are delicious the day they have been baked, they will stay delicious for a few days. The sourdough discard helps keep them soft. Store the cookies in an airtight container at room temperature.

To freeze the dough, scoop it into portions. Then press each dough ball down a little (this will ensure the cookies will spread), place them on a lined baking sheet, and freeze until solid. Then transfer the frozen dough balls to a freezer bag or container. Bake directly from frozen, adding 1-2 minutes to the baking time.

Once fully cooled, they freeze well - just store them in an airtight container for a treat anytime. Allow them to thaw at room temperature.

Customize Your Sourdough Oatmeal Cookies

Here are a few fun add-in ideas to spruce up your gluten free sourdough discard oatmeal cookies

• Dark Chocolate: For a sophisticated touch, chop up a high-quality artisan chocolate bar (65% or darker).
• White Chocolate: white chocolate and oats are one of my favorite cookie combos. Just make sure to use some high-quality white chocolate.
• Butterscotch Chips: add some butterscotch chocolate chips and turn them into Gluten Free Oatmeal Scotchies
• Toffee: Add chopped-up Heath bars to the cookies. So good!
• Dried Fruit: cranberries or dried cherries would work fabulously in this gluten-free cookie recipe, or add raisins to make sourdough oatmeal raisin cookies
• Nuts: Mix things up with chopped pecans, peanuts, or walnuts for extra texture and nuttiness.
• Mini M&M’s: Make them fun and colorful - kids (and adults!) will love them.

Note about Salt in my Recipes

I use Diamond Kosher Crystal Salt in all of my recipes unless otherwise stated. If use use a different brand or kind of salt in your kitchen please adjust accordingly since some salts can be saltier. If you use Morton’s Kosher Salt please be aware that their salt granules are smaller in size, denser, and crunchier and twice as salty.

Baking in grams

I share my recipes in grams and by weight since baking by weight is the most accurate way to bake. Digital Scales are very affordable and easy to use. You can purchase them on Amazon for less than a set of measuring cups. For small amounts under 10 grams, I like to use this Precision Pocket Scale. Measuring cups are very inaccurate which can cause significant errors when it comes to gluten-free baking or baking in general. Especially since I bake with gluten-free flours which weigh differently than “regular” flours. I do provide some ingredients like spices and leavening agents in measuring spoons. To learn more about Baking with a digital scale, make sure to check out my post about Baking by weight.

Note about Ovens and Oven Temperatures

All my recipes are tested and developed with a conventional oven. I always bake my baked goods on the rack placed in the MIDDLE of my oven. This way the heat coming from the bottom will not burn my baked goods.

If you are baking with convection (fan-forced), please adjust the recipes accordingly. Convection oven can cause baked goods to dry out quickly and still be raw inside. Since takes at least 15-20 minutes for a standard American Oven to be fully preheated. I highly recommend investing in an Oven Thermometer.

Substitutions and Modifications

Any dietary or ingredient modifications/substitutions to this recipe may alter the end result in appearance and taste. I test my recipes several times as published in this post and The Gluten Free Austrian Blog is not responsible for the outcome of any recipe you find on our website.