Peanut Butter Oatmeal Bars have a chewy oatmeal cookie base with thick swirls of peanut butter fudge. Easy to make and they freeze well too!
Making cookie bars is so much easier than individual cookies, and this recipe does not disappoint. You’ll love how easy they are to make, and peanut butter lovers will rejoice!
This recipe for oatmeal bars with peanut butter was originally published in October 2016. The photos and recipe notes were updated in July 2025.
Aimee’s Recipe Notes
Taste & Texture: Chewy oatmeal cookie bars with a sweet, nutty flavor from the swirls of peanut butter fudge.
Ease: Much like my chocolate revel bars, these can be made in and out of the oven in under an hour!
Flavor Substitution: My butterscotch revel bars have the same chewy texture, but with a butterscotch twist.
Allergies? Swap out the peanut butter for Biscoff and the peanut butter morsels for white chocolate chips.
Top Tip: Allow cookie bars to cool completely before slicing. This lets the fudge layer to set up.
These are really amazing! My kids loved it!
– Toni
Ingredients You’ll Need
Scroll down to the recipe card below for the full list of ingredients and measurements. Here are a few highlights.
- Light Brown Sugar – The molasses in brown sugar makes for a chewy cookie layer with a hint of sweet caramel flavor. You can use a dark brown sugar too if you prefer.
- Creamy Peanut Butter – Peanut butter is the most important flavor element in the cookie layer! Choose a shelf stable peanut butter like Jif or Skippy for best results.
- Pure Vanilla Extract – Helps achieve that classic peanut butter cookie flavor. Pure vanilla is always best! Or use my homemade vanilla extract.
- All-Purpose Flour – Gives structure to the cookie layer and topping. Be sure to use my tips and tricks on how to measure flour properly so you don’t end up with dense, dry cookie bars.
- Quick-Cooking Oatmeal – Adds chewy texture and a hint of hearty flavor to these sweet dessert bars. You can also use old fashioned oats, just avoid steel cut oats for this recipe.
- Sweetened Condensed Milk – Creates the base of the peanut butter fudge layer.
- Peanut Butter Chips – The final touch to add rich peanut buttery flavor to the creamy fudge layer of the bars.
How to Make Peanut Butter Oatmeal Bars
What I love about cookie bars is how easy they are to make. Unlike peanut butter cookies, these bars come together so quickly, with just one bake time (no need to make tray after tray of cookies).
Make the cookie dough: Cream the butter, sugar, and peanut butter together until light and creamy. Then mix in the baking soda, eggs, and vanilla. Add the flour and oats last to finish the dough.
Layer in the pan: Press ⅔ of the cookie dough into the bottom of your prepared pan.
Make the peanut butter fudge layer: Heat the sweetened condensed milk and butter in a saucepan until the butter is melted. Then add the peanut butter chips and stir until melted and smooth.
Top it off: Pour the peanut butter fudge mixture over the top of the oatmeal cookie batter and spread it to all the corners of the pan, making a smooth surface. Drop the remaining 1/3 cookie dough evenly in little clumps over the peanut butter fudge layer.
Easy Cookie Recipes
Love cookie bars? My peanut butter cookie bars are a delicious option, and they’re loaded with peanut butter and Reese’s too! Or give my delicious M&M cookie bars a try next for a delicious, chewy treat.
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Peanut Butter Oatmeal Cookie Bars Recipe
Ingredients
- 1 cup unsalted butter softened (divided)
- 2 cups light brown sugar packed
- ½ cup creamy peanut butter
- 1 teaspoon baking soda
- 2 large eggs
- 2 teaspoon vanilla extract
- 2 cups all-purpose flour
- 3 cups quick-cook oatmeal
- 1 can sweetened condensed milk 14 ounce
- 1 package peanut butter chips 11 ounce
Instructions
- Preheat oven to 350°F. Line a 15x10x1-inch baking sheet with parchment paper. Set aside.
- In a large bowl, beat 14 Tbsp of butter (reserving the extra two for later), brown sugar, and peanut butter until well blended. Add in baking soda, eggs and vanilla extract. Beat until combined. Add flour and oats and mix until blended. Set aside.
- In a small saucepan, combine sweetened condensed milk and 2 Tbsp butter. Heat over low heat until butter is melted. Fold in peanut butter morsels and stir constantly until melted and smooth.
- Press 2/3 of cookie dough into bottom of baking sheet. Keep pressing with your fingertips, it will fit, honest!! Pour peanut butter mixture over top of cookie dough and spread evenly. Drop remaining dough by teaspoon over the top (will not cover completely, that’s okay).
- Bake for 25-28 minutes until browned. Cool completely. Cut and enjoy. Store in airtight container (best when chilled)!
Notes
- If peanut allergy, substitute Biscoff for the peanut butter, and use white chocolate morsels for the fudge layer!
- Be sure to choose a baking sheet that has at least 1-inch sides to avoid an oven disaster!
- As you press the cookie dough base into your pan, press it into all the edges and corners. Try to ensure the bottom layer is spread as evenly as possible, so your cookie base has an even thickness throughout.
- Keep your stove at a low temperature as you warm up the condensed milk, butter, and peanut butter chips. This helps avoid burning the bottom since the main goal is to melt everything together gently.
- Store cookie bars at room temperature in an airtight container for up to one week. Or freeze bars for up to 3 months.
Very easy to make, I accidentally used instant oats the first time and it turned out to be more of a fudge than a cookie bar. (Still tasty though not what I had in mind). The second time around I used normal oats (I can only get either instant or “normal” oats, no quick cook at the local supermarkets) – the cookie bar came out as per your pics and I am very happy with the result.
Early on in your article you write about using butterscotch chips in the recipe, but in the actual recipe you call for peanut butter chips, which is correct please
This recipe calls for peanut butter chips, however I do have a butterscotch version, which I reference too.
These are fantastic! They taste like peanut butter fudge wrapped in a soft, chewy peanut butter cookie. This recipe is now on my regular rotation. Thank you!
Oh I am so glad.
I end up baking from the same books over and over too! That peanut butter layer in these bars was to die for!!! I can’t wait to make them again!!!
Going to make these for our family get together this weekend!
These look amazing! I know they won’t last long in my house. Can’t wait to make them.
These are really amazing! My kids loved it!
I made these today and wished I had followed my gut and used a bigger pan. Now I have an oven to clean.????????
all things peanut butter=good! love these bars!
MMmmm thse looked scrumptious on Instagram ( I think thats where I first saw them). I have never made revel bars but clearly need to!!
The best combination ever ! Thank you !
I do go back to the same cookbooks again and again. They’re like old friends!
And these bars are a new friend I need to make!
Awww, “old friends.” So true!!!
These bars look splendid and gooey!
Love their chocolate revel bars! Can’t wait to try your peanut butter version!
These bars look amazing! I Love peanut butter, I look forward to trying these. I feel I should double up because I doubt the family would see any of the first batch!
Wow – what a decadent adaptation of those Revel bars you initially found in your Better Homes and Garden Cookbook. These look sinfully delicious – my daughter and her friends would so enjoy these bars! Thanks so much Aimee.