Oat Flour Brownies are naturally gluten-free, with a perfectly fudgy texture. They taste like the real thing, and I love how you don’t need to use multiple flours, or nut butters, to make this recipe. It couldn’t be easier!
What You Should Know About Using Oat Flour
Oat flour is naturally gluten-free, but it’s important to know that oats can be contaminated with other gluten-containing grains during the manufacturing process. So, be sure to buy a package that is labeled “certified gluten-free” if you are serving these brownies to someone who is sensitive to gluten.
Tip: You can make homemade oat flour, too! In my tutorial, I’ll walk you through how to swap oat flour in other recipes using a simple formula. All you need is oatmeal to get started.
Making an oatmeal brownie also requires some patience, because oat flour tends to be crumbly when compared to other gluten-containing flours.
There are two ways to battle this:
- Use more eggs for structure (if you use 2 eggs, you’ll get a cake-like brownie)
- Wait for the brownies to cool completely (this is your only option if you want a fudgy brownie)
If you cut into oat flour brownies while they are warm, they will start to fall apart as you slice them. This is probably no big deal if you’re just making these for your family at home, but if you want nicely sliced brownies, you’ll need to wait for these to cool down completely.
When they are totally cool, they firm up and will slice much better!
Ingredients You’ll Need
What’s in oat flour brownies?
- Oat flour (which is simply ground-up oatmeal)
- Granulated sugar (I use coconut sugar)
- Cacao powder
The combination is super-simple, and the results are delicious! No starches or gums required for this gluten-free brownie recipe.
If you want to make vegan brownies, you can use coconut oil as a swap for the butter, and use a flax egg instead of the chicken egg. (See the notes in the recipe below for tips!) The brownies will be slightly more fragile in this instance, so just keep that in mind.
How to Make Oat Flour Brownies
1. Mix. Add the oat flour, coconut sugar, cacao powder, baking soda and salt to a large bowl, and whisk to combine.
Then add in the wet ingredients, starting with the melted butter, followed by the egg. (Make sure the melted butter isn’t too hot, so it won’t start to cook the egg.) Stir well, creating a thick batter, then fold in the chocolate chips.
2. Bake. Lightly grease an 8-inch square baking dish, then press a piece of parchment paper into the bottom of the pan, so the brownies will be easy to remove later.
Transfer the batter to the prepared pan, and use a spatula to flatten the batter into the bottom of the dish evenly. It will be thick, and not super-easy to spread. You can sprinkle a few extra chocolate chips on top, if you’d like to!
Bake these oat flour brownies at 350ºF for 20 to 25 minutes. The brownies might still look jiggly in the middle when you remove them from the oven, but they will firm up as they cool.
Note: I originally started baking these brownies for 30 minutes to get rid of the jiggle in the center, but the brownies become too crispy around the edges for me with that cooking time. If you like brownies with a softer, almost gooey center, then go with the shorter cooking time.
3. Cool completely. These brownies will be very fragile when they are warm! Do not slice them until they are totally cool, which can take up to 2 hours depending on the temperature of your kitchen. Gluten-free baked goods tend to be crumbly, but this issue improves greatly when the brownies are at room temperature, or chilled.
When the brownies are no longer warm, you can use a sharp knife to slice them into 16 pieces. The edge pieces will get crispy, and the middle pieces are almost fudge-like. (My favorite!)
Note: These brownies will rise more around the edges and are slightly more flat in the center. This doesn’t seem to be an issue for my family members who all love them, but I thought I’d mention that this is “normal” if you experience it, too.
Store any leftover brownies in an airtight container in the fridge for up to 1 week, or you can freeze these for up to 3 months.
Substitutions & Variations
Can I make brownies without eggs? If you don’t mind a slightly more fragile brownie, you can make this recipe with a flax egg instead. However, for more sturdy results you might prefer to make another recipe instead, like my other gluten-free brownies.
Can I use something other than butter? You can most likely use a 1/3 cup of coconut oil as a swap for butter, since it firms up when chilled. (I haven’t had the chance to test this yet myself, so experiment at your own risk!) If you want a lower-fat recipe, you can swap half of the butter for unsweetened pumpkin puree, but the resulting brownie will be more cake-like in that case.
Can I use a different flour? I wouldn’t make substitutions in this exact recipe, but be sure to check out my other tested brownie recipes below, if you need to use another ingredient.
- Coconut flour brownies
- Almond flour brownies
- Date Brownies
- Avocado Brownies
- Sweet Potato Brownies
- Almond butter brownies
How to Make Peppermint Brownies
For a fun holiday twist, you can swap the vanilla in this recipe for 1 teaspoon of peppermint extract instead. When I tested this version, I used only 1/2 cup of cacao powder instead of the 2/3 cup called for in this recipe, and it reminded me of the minty cookies I used to sell as a Girl Scout!
Add a crushed candy cane on top of the brownies before baking, if you want an extra-festive look. It’s not necessary for flavor, but it does add a nice crunch on top.
Oat Flour Brownies
- Preheat the oven to 350ºF and lighty grease an 8-inch square pan with oil. Press a piece of parchment paper into the bottom of the pan, so the brownies will be easy to remove later.
- In a large bowl, combine the oat flour, cacao powder, coconut sugar, baking soda, and salt. Whisk well to combine.
- Add in the melted butter and stir briefly, to make sure it cools down slightly. Then add in the egg and vanilla extract, and stir again. Fold in the chocolate chips.
- Transfer the batter to the prepared pan and use a spatula to press the batter into the bottom of the pan. This batter is thicker than you might expect, so it won't spread easily. Bake at 350ºF for 20 to 25 minutes. The middle still might look slightly jiggly in the center, but these brownies will firm up as they cool. If you bake them for 30 minutes, the edges will become quite crispy, which is not my preference, but I mention it in case you like that!
- Let these brownies cool completely before slicing into them. Oat flour produces a very fragile brownie that will crumble if you cut into them while they are warm. However, once they cool, they will hold together much better, with a fudgy texture in the middle. You can place them in the fridge to speed-up the cooling process, if you like. Leftovers can be stored in an airtight container in the fridge for up to 1 week, or they can be frozen for up to 3 months.
If you try these oat flour brownies, please leave a comment and star rating below letting me know how you like them.
Reader Feedback: Which flour would you like me to work with next? Let me know if you have any recipe requests!