Tessa’s Recipe Rundown
Taste: Rich, sweet blondies with tons of butterscotch flavor, filled with the spiced decadence of cookie butter.
Texture: Ultra rich, fudgy, and ooey-gooey with slightly crispy edges.
Ease: Super quick and easy recipe that adults and kids will LOVE!
Why You’ll Love This Recipe: Super fun and flavorful twist on blondies.
This post may contain affiliate links. Read our disclosure policy.
Cookie Butter Stuffed Blondies are next level. Indulgent, chewy, rich, and gooey – every bite is pure magic!
The blond sibling to brownies, Blondies are rich, brown sugar-forward, and butterscotchy. As a total chocoholic, it sometimes surprises people that I love Blondies so much – but there’s something so special about a really great Blondie.
This recipe is full of deep caramelized sweetness and a delightfully chewy texture. The Cookie Butter filling brings a level of coziness unlike any Blondie you’ve ever tried.
Free Cookie Customization Guide!
The science-based guide so you can bake perfect cookies every time!
I hope you enjoy these Cookie Butter Stuffed Blondies as much as I do!
Sprinkle of Science
How to Make Cookie Butter Stuffed Blondies
The Pan
These Blondies are ultra-thick and rich, so it’s important to use a pan that conducts heat effectively. Why? Because we want to make sure the Blondies cook through completely but remain gooey in the center, without leaving the center completely underbaked.
For that reason, I highly recommend using a light-colored aluminum baking pan. Glass or ceramic pans will take longer to cook and may result in underbaked or gummy centers, and dark pans may overcook the Blondies, so avoid those types of pans if possible. Learn more about Glass vs. Metal Baking Pans here.
Why Use Dark Brown Sugar?
Dark brown sugar contains more molasses, so it provides a deeper, more complex, caramelized flavor, as well as providing more moisture.
If you don’t have dark brown sugar, you can also use light brown. Learn how to make your own brown sugar here.
The Cookie Butter
The delicious spiced flavor of Cookie Butter reminds me of gingerbread, but with the texture of peanut butter. You can buy the Biscoff brand online or in most grocery stores, and Trader Joe’s also makes their own version.
In these Blondies, the Cookie Butter layer is combined with sweetened condensed milk, creating a simple fudge. It becomes thick and dough-like, as you can see in the photo below.
Layering the Stuffed Blondies
We stuff these Blondies by spreading half the blondie batter in the pan and par-baking for 15 minutes. This allows that layer to semi-set. Then we use our palms to flatten pieces of the Cookie Butter fudge filling, layering pieces on the par-baked Blondie layer. Finally, we spread the remaining Blondie batter on top. Easy peasy!
How to Serve Blondies
These Blondies are ultra-rich, so you can cut smaller squares than most Blondies or brownies. I get 16 slices here, but feel free to slice them even smaller if desired.
Run your knife under hot water and carefully wipe dry between slices, for perfect slices.
How to Store Cookie Butter Stuffed Blondies
Store leftover Blondies inside an airtight container at room temperature for up to 3 days. Re-warm slices in the microwave for 10-15 seconds before serving, for a more gooey texture, if desired.
More Blondie Recipes You’ll Love:
- Blondies Recipe – my go-to classic Blondie recipe
- Raspberry Dark Chocolate Blondies
- Brown Butter Triple Chocolate Blondies
- Gooey Chocolate Chunk Blondies
- Peanut Butter S’mores Blondies
Cookie Butter Stuffed Blondies
Email This Recipe
Enter your email, and we’ll send it to your inbox.
Ingredients
- 2 sticks (227 grams) unsalted butter, melted
- 1 3/4 cups (350 grams) dark brown sugar
- 2 large eggs plus 1 egg yolk
- 1 teaspoon vanilla
- 1/4 teaspoon fine salt
- 2 cups (254 grams) all-purpose flour
- 1 cup (240 grams)
Cookie Butter - 2/3 cup (200 grams) sweetened condensed milk
Instructions
- Preheat the oven to 350°F. Line an 8 by 8-inch light-colored metal pan with foil or parchment paper. Spray with nonstick cooking spray.
- In a large bowl, combine the hot melted butter and sugar with a rubber spatula. Set aside to cool. Add the eggs, egg yolk, and vanilla and stir until combined. Stir in the salt and flour.
- Spread half the batter evenly into the prepared pan. Bake for 15 minutes, or until it just begins to set. Keep oven at 350°F.
- In a heatproof container, microwave the cookie butter and condensed milk in 20-second bursts, stirring between bursts, until warmed through and well combined.
- Using your hands, pick up portions of the Cookie Butter mixture and flatten with your palms. Place on top of the par-baked blondie layer in one even layer.
- Spread the remaining blondie batter over the Cookie Butter layer evenly.
- Return to the 350°F oven and bake for another 30 minutes, or until golden brown and set. Allow to cool in the pan completely. Cut into squares and serve.
Recipe Notes
This post was originally published in 2018 and has been updated with additional baking tips. Photos by Ashley McLaughlin.
So, so delicious!!! However, my cookie butter fudge wasn’t doughy and didn’t resemble the picture above. It was just…very thick liquid? It poured and smoothed on top of the blondie layer like a dream, but when I covered it with the top blondie layer, it got mixed in even when I was very careful spreading the blondie layer on top of it. Once the blondie was ready to eat, the cookie butter layer is gooey and not fudgy.
Any suggestions? I also…cheated…and microwaved the cookie butter in 1 20-sec burst, then 1 40-sec burst, then 1 15-sec burst – could this have affected the consistency? Thanks so much!
It is definitely possible your cookie butter/condensed milk mixture just got too hot in the microwave. I’d recommend doing the 20 second bursts so you can keep a closer eye on the temp. I’m so glad they still turned out delicious for you! 🙂
These are amazing. I have never made blondies before but I love cookie butter, so I wanted to try these. To make it easier to place the cookie butter layer on, I made it first into the shape of my pan on a piece of parchment paper. Then I put it in the freezer for about an hour. After I baked my first layer I was able to just pop on the cookie butter layer easily. I let this cool in the pan for around 2 hours after cooking. Then I cut it into small squares.
The center is mushy, but that is how it is supposed to be (I noticed someone commented that it wasn’t “cooked”). I had no issues cutting and everything remained intact. I think waiting for them to cool is the key. These tasted great and everyone said I need to make again. Wonderful recipe and very easy. Quick to make too.
So glad you enjoyed these blondies!
I made this today and I was disappointed in the consistency. The cookie butter center was totally raw despite baking for for 40mins.
Really really REALLY good recipe! Simple and so delicious!
Could be done with nuttella, peanut butter or tahini. Anyway, with biscoff is just the best!
Thank you for sharing your recipes!
I’m from the UK and never heard of Cookie butter, or at least not biscoff spread that is cookie butter flavoured. Would regular biscoff spread work the same ? And if so, is it the smooth version or does the crunchy version work just as well?
Either way, the pictures of this look incredible !!
We loved this recipe!
Sooo good and rich had to cut into small squares to be safe!
These are so delicious, and I love the texture the filling gets after baking. I’m inspired to try this using a hazelnut spread I found, similar to Nutella but no chocolate. It’s just hazelnut. I have no idea what its comparable to, I found it as a shoprite store brand item. Was going to attempt it in these or maybe brownies but afraid it’ll melt into it, rather than stay as a distinct layer. Also, I dont want to smother the flavor, any thoughts? I really cant stand the idea of trying it only to have it be an epic fail. Was also thinking of using a filling of just the spread with powdered sugar, a few tsp./ tbsp.milk and some vanilla,but that seems as though it’ll melt in even easier. Any insight would be greatly appreciated!
Hi! I live in Sweden where no cookie butter is available, so I wonder if you think it would be possible to use the same technique but with Nutella? I figured since they’re about the same consistency? Thank you for being one of my favourite bloggers btw <3
I haven’t tried with Nutella, but if you give it a shot let us know how it turns out! 🙂
Hi Tessa,
I made this today since I really love cookie butter. The problem is the cookie butter filling burst and leak out of the pan in the middle of baking. Please advise what I’d possibly done wrong since it tastes amazing and would like to make it again without the mess.
I am thinking of making this and my plan was to lay out a layer of cookie butter on wax paper and then freeze. After baking the blondie first layer for 15 minutes I was going to put the frozen cookie butter layer on top. Then the second blondie layer and bake.
did you ???? did you freeze a layer instead?
I did freeze the middle layer and it turned out great. It was easy to put the middle layer on and then top with the remaining blondie batter and place back in the oven.
These look delicious 🙂
These look amazing!! Can’t wait to make them!