Rich blondies get a delicious twist with cookie butter in these Biscoff blondies. A classic blondie batter made with brown butter is blended with creamy cookie butter and chopped Biscoff cookies. More cookie crumbs are sprinkled on top, and the bars bake until gooey in the center with chewy edges.
Cookie butter has become very popular in recent years. It’s smooth and buttery with warm spice notes of cinnamon and nutmeg, and its creamy texture makes it a great addition to baked goods and desserts.
After making a batch of no-bake Biscoff truffles that everyone loved, I wanted more cookie-butter recipes. Blondies—with their buttery, vanilla-forward base—are the perfect vehicle for that spiced-sweet Biscoff flavor.
What is cookie butter?
Cookie butter is a spread made from crushed speculoos (Biscoff) cookies combined with sugar and oil to create a thick, creamy paste. Speculoos are thin, crisp spiced cookies traditionally found in Belgium. The brand Lotus popularized the spread, and the name Biscoff—combining “biscuit” and “coffee”—was created to market the cookies in North America.
Biscoff cookies are flavored with spices like cinnamon, ginger, and nutmeg, giving the cookie butter its distinctive warm, slightly spiced taste. Cookie butter can be used like any nut butter in recipes or as a nut-free alternative for those with allergies.
Today many stores carry their own cookie butter, with Lotus Biscoff and Trader Joe’s speculoos spread among the most well-known.
Ingredients
- Brown Butter – Browning the butter adds a nutty depth that enhances the blondies. The process only takes a few extra minutes but yields much more complex flavor than simply melting the butter.
- Brown sugar – The molasses in brown sugar adds richness and chewiness. Light or dark brown sugar both work well.
- Eggs – Eggs add moisture and structure, helping the blondies hold together.
- Vanilla – Real vanilla extract brightens the flavor; avoid imitation if possible.
- Cookie butter – Lotus Biscoff is the original, but other brands are available. Cookie butter folds into the batter for a concentrated spiced-caramel note.
- Flour – All-purpose flour is ideal. For best results, measure flour by weight or spoon it into a measuring cup and level it off.
- Baking powder – A small amount provides slight lift without making the blondies cakey; they should remain dense and chewy.
- Kosher salt – If using table salt, reduce the amount. Salt balances the sweetness and enhances flavor.
- Biscoff cookies – Coarsely crushed cookies add texture and amplify the cookie-butter flavor; reserve some for topping.
Tips to brown butter
- Cut the butter into tablespoon-sized cubes so it melts evenly. Use a light-colored saucepan so you can see the color change and browned bits.
- Melt the butter over medium heat. It will bubble and foam as it melts. Stir frequently so it cooks evenly and doesn’t burn.
- When the foam subsides and you can see an amber, golden color and fragrant brown bits on the bottom, remove from heat. Scrape the browned bits into the butter—they’re full of flavor.
How to make Biscoff blondies
This is a straightforward one-bowl recipe that uses browned, melted butter, so there’s no creaming step. The batter comes together quickly:
- Combine the cooled brown butter with brown sugar. Whisk in the eggs and vanilla, then fold in the cookie butter until evenly distributed.
- Add the flour, baking powder, and salt, stirring just until combined. Fold in the crushed Biscoff cookies for texture.
- Spread the batter in a prepared 8 x 8-inch pan and sprinkle additional crushed cookies on top.
- Bake until the edges are golden and the center is almost set. Cool completely before slicing for clean bars.
How to store blondies
These blondies don’t require refrigeration. Store them in an airtight container or cover the pan with foil or plastic wrap. They stay fresh for 3–4 days before beginning to dry out.
FAQs
Yes. Cool them completely, then place cut bars in an airtight container or a zip-top bag and freeze for up to 3 months. Thaw overnight at room temperature.
You can, but a 9 x 9 pan will yield thinner blondies that bake faster. For thicker, gooier bars, use an 8 x 8-inch pan.
No. Melted butter will still produce tasty blondies, but browning the butter adds a richer, nuttier flavor that elevates the final result.
Dry blondies are usually the result of too much flour. Measure flour accurately—ideally by weight. If using measuring cups, fluff the flour, spoon it into the cup, and level it off instead of scooping directly from the container.
For more bar cookies, check out these:
- Fudgy Peanut Butter Cup Brownies
- Brown Butter Peach Blondies
- Salted Peanut Bars
- Chocolate Peanut Butter Rice Krispie Treats
Tag me on Instagram @themarblekitchenblog if you make these blondies, and please leave a star rating and comment below. Enjoy!
Biscoff Blondies
Ingredients
- ¾ cup unsalted butter cubed
- 1 ½ cups brown sugar packed (light or dark)
- 2 eggs
- 2 teaspoons vanilla extract
- ½ cup cookie butter
- 2 cups (240 grams) all-purpose flour
- 1 teaspoon baking powder
- 1 teaspoon kosher salt
- 1 cup coarsely crushed Biscoff cookies about 14 cookies
- additional crushed cookies for the top
Instructions
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Line an 8 x 8-inch pan with parchment paper, leaving an overhang on two sides. Preheat the oven to 350°F (175°C).
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Melt the butter in a small saucepan over medium-low heat and cook until it turns golden brown and smells nutty, about 5–7 minutes. It will foam as it cooks—stir and watch the color under the foam so it doesn’t burn. Remove from heat and cool for 5 minutes.
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In a medium bowl, mix the browned butter with the brown sugar until combined. Add the eggs and vanilla and mix well.
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Stir in the cookie butter until evenly incorporated.
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Add the flour, baking powder, and salt, stirring until just combined and leaving a few streaks of flour. Fold in the crushed cookies gently until the flour is absorbed—avoid overmixing.
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Transfer the batter to the prepared pan and smooth the top. Sprinkle extra crushed cookies on top if desired.
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Bake for 20–25 minutes, until edges are golden and the center is nearly set. Cool completely before cutting into bars.