These tender, soft, and decadent Chocolate Chip Oatmeal Blondies with Buttercream Frosting are a cross between an oatmeal cookie, blondie, and cookie cake. They're perfect for a party dessert or to enjoy as an evening treat with a tall glass of cold milk!
Table of Contents
About these Blondies
Did you know that January was National Oatmeal Month? I didn't either, but better late than never! 😜 Let’s celebrate with these Chocolate Chip Oatmeal Blondies with Buttercream Frosting!
If blondies and cookie cake had a baby, it would be these oatmeal blondie bars. They're so tender, soft, and decadent—and the addition of some chocolate chips and fresh buttercream makes them even more delicious! You could even swap the chocolate chips for some raisins if you love the classic combo.
I love to enjoy these blondie bars with a tall glass of milk. It makes for such a wholesome and satisfying snack. You won't regret making a batch to enjoy all week long! If you love blondies, I think you'd also love these Cranberry White Chocolate Bars or these Gingerbread Blondies too!
Recipe Ingredients
- Butter: Leave this out on the counter so it comes to room temperature. It makes our blondies rich and chewy.
- Sugar: Grab both brown sugar and white cane sugar. Using a mix of both results in the perfect texture.
- Oat Flour: I used Bob’s Red Mill brand. You could also make your own by pulsing some rolled oats.
- Oats: Whole oats give great texture to these blondies. Avoid using quick oats, as they'll become much to mushy in this recipe.
- Chocolate Chips: I used mini chocolate chips. But feel free to use whatever you like. Regular chips, chunks, or a chopped chocolate bar are all options.
- Powdered Sugar: Makes the frosting sweet and a smooth texture as compared to the granular result you’d get with regular sugar.
See the recipe card below for a full list of ingredients and measurements.
How to Make This Recipe
1. Preheat the oven to 350°F. In a large mixing bowl, beat together room temperature butter, brown sugar, and white sugar with a hand mixer. It took me about 3-5 minutes.
2. Next, add in eggs and vanilla extract. Then, beat again.
3. Pour in the oat flour, salt, baking powder, and rolled oats and mix so wet and dry ingredients are well combined. You'll need to crank up the speed that arm strength. This will be a thick batter. Fold the chocolate chips into the batter with a rubber spatula.
4. Grease a 9x13 Pyrex baking dish and pour in the batter. You may need to spray the rubber spatula with cooking grease so you can spread it easier. I used two butter knives to pull the batter to all sides of the pan. Bake 25-30 minutes or until a toothpick inserted in the center comes out clean.
5. While the blondies bake, let's make the frosting. Beat together all ingredients in a mixing bowl. Start with 1 tablespoon of almond milk and continually add 1 tablespoon until the frosting is blended. You may need more or less of the almond milk, so keep an eye on it. I used a piping bag & frosting tip to get the detail on these blondies. You can easily use a rubber spatula to spread in on the blondies, too. Whatever works for you!
How to Brown Butter
Blondie tip: Brown your butter!
Browning butter is the process of taking regular butter just past its melting point to toast the milk solids. Doing this brings out the nuttier, richer, and caramel flavors of butter and really takes this recipe up a notch! Here’s the details on how to do it:
- You’ll need a small saucepan and whisk or spoon. I suggest a stainless steel or lighter color pan so you can see when the butter begins to change in color.
- Heat your pan over medium-high heat. Cut your butter into slices and add it to the heated pan. It’s best to use unsalted butter for this.
- Allow your butter to melt, stirring frequently to keep milk solids from sticking to the bottom of your pan.
- After a couple of minutes, your butter should begin to foam and browned specks should appear. Watch your butter closely! It should turn from yellow to a golden brown.
- Once the butter becomes a deep golden brown, transfer to a heat-proof bowl. This will stop the cooking process.
Burnt butter, which will leave black bits on the bottom of your pan, will have a very bitter flavor. If this happens, unfortunately, you'll need to toss it and try again. If you are nervous about this process, I recommend following the same steps on a lower heat to slow down the cooking process.
Here’s a quick video if you’re looking for a visual.
Note that some of the butter evaporates while it’s browning, so you end up with slightly less brown butter compared to the amount of butter you started with. A good rule of thumb is for every stick (8 tablespoons) of browned butter, you need an extra tablespoon of solid butter to make it.
Recipe FAQs
Here's a tip that my family has been practicing since I was a kid: Keep a piece of sandwich bread in the same container as your blondies. A large Tupperware is best. I usually use the end slice of a loaf that is likely going in the trash anyway. All of the moisture in the bread will be drawn out by the blondies to keep them nice and soft.
Just throw rolled oats in a food processor and pulse. If your food processor is not high powered, however, you may want to consider buying your oat flour pre-ground. If you can't achieve a very fine flour, the texture of your blondies will be compromised.
Chocolate chips are only the beginning! Since these blondies are oat flour based, my mind first goes to raisins. Adding some walnuts, pecans, or other nut of choice would add some texture. You could also try adding peanut butter chips, butterscotch chips, or white chocolate chips. Heck, try some chopped up candy bars!
More Recipes You'll Love
Love this recipe? Please leave a 5-star 🌟🌟🌟🌟🌟rating in the recipe card below & if you really like the recipe consider leaving a comment further down. Thanks for visiting!
Recipe
Oatmeal Chocolate Chip Blondies Recipe
Equipment
- Sauce pot
- Handheld mixer
- Mixing bowls
- Measuring cups and spoons
- Rubber Spatula
- 9x13 baking dish
- parchment paper
- plastic bag for piping
- scissors
Ingredients
For the blondies
- 1 stick room temperature butter
- 1 cup brown sugar
- ½ cup white cane sugar
- 2 eggs
- 1 tsp vanilla extract
- 2 ⅓ cups oat flour
- 1 ½ tsp baking powder
- 1 cup rolled oats
- ½ cup mini chocolate chips
For the frosting
- ⅓ cup room temperature butter
- 1 ½ cup powdered sugar
- 1-3 tablespoons almond milk
Instructions
- Preheat the oven to 350°F.
- In a large mixing bowl, beat together room temperature butter, brown sugar, and white sugar with a hand mixer. It took me about 3-5 minutes.
- Next, add in eggs and vanilla extract. Then, beat again.
- Pour in the oat flour, salt, baking powder, and rolled oats. Before mixing the batter again, lightly stir the dry ingredients on top.
- Combine wet and dry ingredients. You'll need to crank up the speed that arm strength. This will be a thick batter.
- Fold the chocolate chips into the batter with a rubber spatula.
- Grease a 9x13 Pyrex baking dish and pour in the batter. You may need to spray the rubber spatula with cooking grease so you can spread it easier. I used two butter knives to pull the batter to all sides of the pan.
- Bake 25-30 minutes or until a toothpick inserted in the center comes out clean.
- While the blondies bake, let's make the frosting. Beat together all ingredients in a mixing bowl. Start with 1 tablespoon of almond milk and continually add 1 tablespoon until the frosting is blended. You may need more or less of the almond milk, so keep an eye on it. I used a piping bag & frosting tip to get the detail on these blondies. You can easily use a rubber spatula to spread in on the blondies, too. Whatever works for you!
Nutrition
Notes
Looking for this in MyFitnessPal?
If you're using MyFitnessPal, search 'A Paige Of Positivity' and find Oat Flour Chocolate Chip Blondies calories and nutrition facts. Disclaimer: for most accurate macronutrients and caloric breakdown, it is recommended that you input each ingredient into your MyFitnessPal food diary.
I’d love to hear your thoughts in the comments below. It’s my passion to create dishes that can be shared with others. Tell me something you loved or just say hi!
Lindsey Reich says
5 stars on these FOR SURE. They were so good!! I wish I used less oat flour to get a more gooey texture. And I used oat milk instead of almond milk for the frosting - still wonderful.
Amy says
Truth be told — I did not make these myself, but I DEFINITELY ate them! Delicious and hearty! I paired the bar with a cup of chai latte and thoroughly enjoyed!
Sydney Van Acker says
I'm all about THICK cookies and this blondie is essentially that. Kinda like cookie cake. It is SO good
Courtney Paige says
AHHH-mazing! Especially with the buttercream. Love it!