September 27, 2021

Oat Flour Blondies

Rarely do you hear a blondie described as chewy and flavorful but these are it: made with oat flour, in ten minutes and in one bowl. 

4.87 from 23 votes
Yield: 16 bars
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oat flour blondies

I am a little obsessed with oat flour. I use it to make pancakes, waffles and have been using it my chocolate chip cookies for years (I pretend it’s to add nutrition but really I just love the flavor). In these blondie bars oat flour is especially wonderful because where most blondies are a bit dry and flavorless, making them brownies’ inferior cousin, these will rival your favorite brownie no joke. They are moist, full of flavor and super chewy. I put mine in the fridge for about an hour and, cold they were incredible. I would eat these bars without the chocolate and that is saying something. 


Ingredients for Oat Flour Blondies 

Butter: Cannot be substituted with an oil. The combination of butter and brown sugar is the base of a good blondie (what gives them that butterscotch flavor). If you want to brown it see the FAQ below. 

Brown sugar: Light or dark is fine. Don’t substitute with granulated or the bars will be quite dry and lacking in flavor. 

Eggs: Whole and large. No substitutions. 

Oat flour: Use store-bought oat flour rather than ‘homemade’.  You can also toast the flour for more flavor: 350 F, spread out onto a cake pan for about 10 minutes. No substitutions here as this is the star of our bars!

Chocolate chips: Dark good quality chips although really whatever you like best will work here. 

Salt & vanilla: Both of these give flavor to the bars, don’t skip them. 

How to make Oat Flour Blondies 

  1. Partially melt the butter. 
  2. Add the sugar and melt the butter fully and whisk to combine. 
  3. Whisk in the flavorings and eggs. 
  4. Fold in the flour and chocolate. 
  5. Bake! 


FAQ on Oat Flour Blondies 

Can I brown butter for oat flour blondies? 

The flavor of brown butter here is actually really good. The reason I don’t do it for this recipe is that it does compromise the moisture level and chewiness factor. If you would like to brown the butter, brown more than you need for the recipe and then measure it out according to what’s listed below. 

Can I make my own oat flour? 

Homemade oat flour is almost impossible to get as fine as store-bought, it is also made from whole oat groats (so before it’s husked) and in Stella’s words “provides more thickening power“. I definitely recommend and prefer store-bought. Arrowhead Mills makes a wonderful oat flour. 

Can I make blondies eggless? 

I would look into flax eggs if I were to do it, but I can’t guarantee it’ll yield a good result. Your best bet is to find a recipe designed to be eggless. 

How best to store blondies? 

In an airtight container. 

Can I make blondies ahead of time? 

Yep! These taste great for days and keep a nice chew. See above for storage suggestion. 


Recipe for Oat Flour Blondies 

Oat Flour Blondies

Rarely do you hear a blondie described as chewy and flavorful but these are it: made with oat flour, in ten minutes and in one bowl. 
oat flour blondies
Prep Time: 10 minutes
Cook Time: 29 minutes
Yields: 16 bars
4.87 from 23 votes


  • 170g or ¾ cup unsalted butter cold is fine
  • 300g or 1 ½ cups brown sugar dark or light
  • ¾ teaspoon fine sea salt
  • 1 teaspoon pure vanilla extract
  • 1 large egg plus 1 large yolk
  • 190g or 1 ¾ cups oat flour store-bought
  • up to 1 cup dark chocolate chips


  • Preheat the oven to 350 F. Grease an 8 or 9” square pan and line with two parchment slings (one on each side).
  • Set the butter in a large heatproof bowl and melt the butter in the microwave for about 1 minute, it shouldn’t be fully melted.
  • Add the sugar and stir to combine, return to the microwave for another 30 seconds. Whisk the mixture quickly until it gets shiny and cohesive. Add the salt and vanilla and whisk to combine.
  • Add the egg and yolk and whisk for a full minute, the mixture will turn glossy. Sprinkle in the oat flour (or sift it in if it's lumpy) and stir in the chocolate chips and fold with a rubber spatula.
  • Pour batter into the prepared pan and bake for about 30-35 minutes, until the center puffs up a bit and a cake tester comes out with bits but is not gooey. Let cool in the pan and slice once firm.
  • Store in an airtight container. They’ll be nice and chewy for days. If you like you can store these in the fridge, they are chewy and fudge like when cold.


I often like to let my batter sit for at least half an hour at room temp before baking, this helps the oat flour dissolve better. 

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Recipe Reviews

  1. Took the risk and tried these for the first time for a party and they were a huge hit! Like another commenter I doubled the recipe and mine baked for about 40 minutes. I did add a little pinch of baking soda as I didn’t want them to be too dense, and added in a bit more chocolate than the recipe called for. I also had good results with making them dairy-free using country crock plant butter sticks. I will absolutely make these again and thanks so much for a fantastic recipe!

  2. 5 stars
    I made these this evening with homemade oat flour and they were perfect! I love that this recipe is so quick and easy. I doubled the recipe to make in a 9×13 pan. I will definitely be making these again!

  3. 5 stars
    Just made these for my daughter who can’t eat gluten. Probably the best baked treat she’s ever had! These oat flour blondies are absolutely delicious! So easy to make and they have a great taste and texture unlike many gluten free recipes. Will be making these often. I used Kerigold butter, Gold Medal gluten free oat flour, & Guittard semisweet chocolate chips.

  4. 5 stars
    These are delicious! SO happy to find a naturally gluten free recipe that is this good. Definitely a keeper for all to enjoy not just GF folks! Thank you! Resubmitted this comment with the 5 star rating!

  5. 5 stars
    These are absolutely incredible. So yummy. Discovered this recipe about a month ago and have made them several times.

  6. 5 stars
    I am forever converting all of Sam’s recipes to be GF, and loving the results – she never disappoints! So, when I saw that this naturally GF recipe came in first place in flavour, and second place overall in the pancake princess’ blondie bake-off, I had to make them immediately. An instant hit! I blended my oats in the vita mix as I didn’t have oat flour in hand, and the texture was still perfection.

  7. 5 stars
    I love this recipe! Even my husband, who isn’t a blondie fan, LOVED these! The oat flour worked perfectly… so tasty and the best chewy texture.

  8. 5 stars
    Dear Sam, before I had my way with your blondies, I read some reviews on your site. Lo and behold, there was a comment from me from almost 1 1/2 years ago. Because you were so kind to respond to my comment, how could I not give my review, after finally baking them off. OMG, these are everything you stated they would be, and more. My only tweak was to do as one of your reviewers suggested. I did brown the 6 oz. of un-salted butter, which of course evaporated some water, and then I added a little water back, bringing the weight once again to exactly 6 oz. Before adding the chocolate I chose to let the batter rest for a while until tepid, versus warm so as not to melt the chips. These bars are stunning, and piggish me has turned an 8 inch square pan intro 6 decadent bars. These were a revelation, and will be made for all of my friend family whom I love. Your recipes are so thoroughly vetted before you share them, and I can’t thank you enough for this quality of yours. Yesterday I received 3 pounds of skinned raw hazelnuts, because I’m going to make your latest sharing of hazelnut butter chocolate chip cookies!

    • Jeff, wow what a great review – thank you so much! So glad they lived up to expectation. P.S. I had to breathe a sigh of relief when you said you added some water back to the butter 😉

  9. 5 stars
    This recipe is delicious and wonderfully easy. I used Bob’s Red Mill oat flour. Thanks for including recipes with oat flour on your blog—I was unsure how to use it but after using it in this recipe, your Emergency Brownies and Brown Butter Muffins it is a new favorite!

  10. 5 stars
    Perfectly chewy and delicious, but so simple!
    Perfect recipe as is, of course, but also versatile. I’ve made a couple times. I took the gamble on homemade oat flour as I keep a large amount on hand, and it turned out well for me.
    I also have tried browned butter, using the following method to guard against the moisture loss Sam mentions: Weigh out the butter in your pan, an. Brown and cool partially, then add to your baking bowl, weighing the grams of the finished browned butter. Then, add water to make up the difference of the original grams called for, since water is what evaporated from the butter during the browning process. (You should have no more than 170 grams of browned butter + water in your baking bowl before you add the brown sugar and continue with the recipe.) I’m sure there are differing opinions here but this method has worked well for me in this and other recipes, thankfully!
    I’ve also tried omitting chocolate and adding 2-4 Tbsp sprinkles for funfetti blondies; it works!

  11. 5 stars
    Another winner from Sam! This recipe is so simple but produces such complex flavor. The oat flour is a terrific GF option and goes so well with brown sugar and dark chocolate. I added flaky salt on top just for fun. Thank you Sam!!

  12. 5 stars
    These are absolutely amazing – so fudgy and buttery! I used blended oats in lieu of oat flour, and it still came out delicious.

  13. 5 stars
    Super easy-to-follow instructions! I love the flavor and texture of the oat flour. I made sure to get good chocolate too. It was a hit with my coworkers!

    • 4 stars
      The taste on these is great. The texture in the middle is more greasy and squishy than I’d like, but I might test adding more flour to see if the texture is a little better. Good stepping stone recipe though, thank you!

  14. 5 stars
    Made these today, but did in fact make my own oat flour for the recipe and they were perfection. I ground Quaker old fashioned oats in my regular vita-mix (pulsing working best!) until they became a fine flour. Easy peasy and these blondies could not have been better! Will be my go-to recipe, thanks!

  15. 5 stars
    These were sooooo good. Lots of butterscotch flavor. They came together very easily, I even started with one stick of frozen butter. I had AP flour and they were delicious. I can’t wait to try again with proper oat flour.

  16. 5 stars
    I whipped these up almost in less time than it took the oven to preheat! Taste and texture were both spot on, I really enjoyed the chewy corner piece. I used 3/4 tsp Diamond kosher salt in the dough and a sprinkle of Maldon on top before baking. I’d hold back some chocolate chunks next time to place on top of the batter after scooping it into the pan to get the glamor shot like Sam’s.

    • 5 stars
      I made these & they came together so fast! I swapped about a quarter cup of the chocolate chips for butterscotch chips and they turned out great!

  17. 5 stars
    5 stars strictly from your descriptive sharing how moist this will be. Is it possible to get your preferred brand of the oat flour, which seems so important to your recipe….I really want to make these in the coming week. If you feel there is no difference in the various oat flours out there, I guess that will suffice. Thank you for your site.

    • Hi Jeff! I use arrowhead mills (I usually find it at whole foods in the baking isle for $3.50 a bag, less if it’s on sale). Looking forward to you making them, hope they live up to that description!