These Biscoff Blondies are dense, chewy, and fudgy in the center with crisp golden edges and irresistible caramelized Biscoff flavor in every bite. Made in one bowl with no mixer, they come together in minutes and are topped with crushed Biscoff cookies for the perfect finishing crunch.
If you love Biscoff spread (and honestly, who doesn’t?), these blondies are about to become your new obsession. The batter is packed with smooth Biscoff spread, studded with crushed Biscoff cookies, and finished with a gorgeous warm Biscoff swirl on top that caramelizes as it bakes into something truly magical.
No fancy equipment, no complicated steps - just one bowl, a spatula, and 25 minutes in the oven. These are the kind of bars you’ll make on a weeknight and have to stop yourself from eating straight out of the pan.
For more Biscoff recipes, try my Biscoff brownie blondies or Biscoff brownies next!
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Why You’ll Love These Biscoff Blondies
- One bowl, no mixer: Everything comes together in a single bowl with just a whisk and spatula. Less mess, less effort, more blondies.
- Intense Biscoff flavor: Biscoff spread in the batter AND crushed cookies mixed in AND a swirl on top means every bite is packed with that signature caramelized speculoos flavor.
- Perfectly chewy texture: Dense, fudgy centers with slightly crisp edges - exactly what a great blondie should feel like.
- Ready in under 30 minutes: From bowl to oven in about 10 minutes, baked in 22-25 minutes. These are dangerously fast to make.
- Only 8 ingredients: Simple pantry staples plus Biscoff spread. That’s it.
Ingredient Notes
- Unsalted butter : Melted butter gives these blondies their dense, fudgy texture - no creaming required. Make sure it’s slightly cooled before adding the egg so you don’t scramble it. Unsalted lets you control the salt level.
- Light brown sugar : Brown sugar is essential here - it adds moisture, chewiness, and a deep caramel flavor that pairs beautifully with the Biscoff. Pack it firmly into your measuring cup. Don’t substitute white sugar or your blondies will be flat and dry.
- 1 large egg + 1 egg yolk: The whole egg gives structure while the extra yolk adds richness and keeps the centers ultra-fudgy. This combination is the secret to that bakery-style texture.
- Vanilla extract : Rounds out and enhances the caramel notes in the Biscoff. Pure vanilla extract is always worth it here.
- Biscoff spread : This goes straight into the batter for deep, pervasive Biscoff flavor throughout every bite. Use the smooth variety for best results - crunchy can affect the texture of the batter. You can use trader joe's speculoos cookie butter as well.
- All-purpose flour : Gives the blondies structure without making them cakey. Measure carefully - spoon the flour into your measuring cup and level it off, or weigh it. Too much flour makes dry, crumbly blondies.
- Baking soda: Just enough lift to keep the blondies from being too dense without making them cakey.
- Salt : Balances the sweetness and enhances the caramelized Biscoff flavor. Don’t skip it.
- Lotus Biscoff cookies: Roughly crushed and folded into the batter, these add little pockets of crunchy spiced cookie throughout. Don’t crush them too fine - you want chunky pieces for texture.
Substitutions & Variations
- Make them Biscoff chocolate chip blondies. Fold ½ cup of dark or milk chocolate chips into the batter along with the crushed cookies. The slight bitterness of dark chocolate is a perfect contrast to the sweet caramelized Biscoff.
- Add white chocolate chips. White chocolate and Biscoff is a classic pairing - fold in ½ cup of white chocolate chips for an extra creamy, sweet bite.
- Use Biscoff cookie butter crunch. If you can find the crunchy variety of Biscoff spread, use it in place of the smooth spread in the batter for extra texture throughout.
- Make them gluten-free. Substitute the all-purpose flour with a 1:1 gluten-free flour blend. The texture stays very similar. Make sure your Biscoff cookies are gluten-free too if needed.
- Double the batch for a 9×13 pan. Simply double all ingredients and bake in a 9×13 inch pan. Add 5-8 minutes to the bake time and check for doneness at the 30 minute mark.
- Add a sprinkle of flaky sea salt on top. Right before baking, a pinch of flaky sea salt over the Biscoff swirl takes these from great to absolutely incredible.
Step-by-Step Instructions
Here is how to make this Biscoff Blondie recipe. Preheat your oven to 350°F (175°C). Line an 8×8 inch baking pan with parchment paper, leaving an overhang on two sides for easy lifting.
Mix the wet ingredients: In a large bowl, whisk together the melted butter, Biscoff spread and brown sugar until combined and slightly glossy, about 1 minute.
Mix in the eggs:Add the egg, egg yolk, and vanilla extract and whisk vigorously for another minute until the mixture is smooth and slightly thickened.
Add the dry ingredients: Add the flour, baking soda, roughly crushed Biscoff cookies and salt to the bowl. Switch to a spatula and fold until just combined - stop as soon as you no longer see streaks of flour. Do not overmix or your blondies will be tough.
Transfer to the pan: Pour the batter into your prepared pan and spread it into an even layer with your spatula.
Add the Biscoff swirl: Warm the 3 tablespoons of Biscoff spread in the microwave for 15-20 seconds until pourable. Dollop it over the top of the batter in 6-8 small spoonfuls, then use a toothpick or skewer to swirl it through the surface. Add extra Biscoff cookies on top if desired.
Bake: Bake for 22-25 minutes, until the edges are golden and set and a toothpick inserted in the center comes out with a few moist crumbs (not wet batter). The center will look slightly underdone - that’s perfect. It firms up as it cools.
Cool completely: This is the hardest step. Let the blondies cool in the pan for at least 30 minutes before lifting out and slicing. Cutting too early gives you messy, falling-apart bars. Cool completely for clean, neat squares.
Tips & Tricks for Perfect Biscoff Blondies
- Don’t overbake. The biggest mistake with blondies is leaving them in too long. Pull them out when the edges are set and the center still looks slightly underdone - it will firm up perfectly as it cools. Overbaked blondies are dry and crumbly.
- Weigh your flour. Measuring flour by volume is inconsistent - too much flour is the most common reason blondies turn out dry. A kitchen scale is your best friend here.
- Cool your butter before adding eggs. If your melted butter is too hot when you add the egg and yolk, you’ll end up scrambling them. Let it cool for 5-10 minutes first, or just touch the bowl - it should feel warm, not hot.
- Use room temperature Biscoff spread. Cold Biscoff spread straight from the pantry can seize up slightly when added to the batter. Let it sit at room temperature for 20-30 minutes before baking for the smoothest incorporation.
- Line your pan with parchment. This is non-negotiable. The Biscoff swirl on top caramelizes beautifully but will stick to an unlined pan. The parchment overhang also makes it incredibly easy to lift the whole slab out cleanly before slicing.
FAQs
You can use crunchy in the batter but it will affect the texture slightly - the crushed cookie pieces in the spread can make the blondies a little less smooth and cohesive. For best results, use smooth in the batter and add your own crushed cookies for texture control.
The two most common causes are too much flour or overbaking. Make sure you’re measuring flour correctly (spoon into the cup and level off, or weigh it at 180g) and pull the blondies out while the center still looks slightly underdone.
Blondies are essentially brownies without the cocoa or chocolate - they get their rich, dense, chewy texture from brown sugar and butter rather than chocolate. Think of them as butterscotch-flavored brownie bars. The base is similar but the flavor profile is completely different.
Storage & Freezing
- Room temperature: Store these biscoff blondies in an airtight container at room temperature for up to 4 days. They actually get chewier and more flavorful on day 2 and 3 as the Biscoff flavor deepens.
- Refrigerator: Store in an airtight container in the fridge for up to 7 days. Let them come to room temperature before eating or warm briefly in the microwave for 10-15 seconds for that fresh-baked fudginess.
- Freezer: These freeze beautifully. Cut into squares, place on a parchment-lined tray, and freeze until solid (about 1 hour). Then transfer to a zip-lock freezer bag or airtight container with parchment between layers. Freeze for up to 3 months. Thaw overnight at room temperature or microwave from frozen for 20-30 seconds.
More Bar Desserts You Will Love
Recipe
Biscoff Blondies
Equipment
- 8*8 square pan
Ingredients
Blondie Batter
- ½ cup (113g) unsalted butter melted and slightly cooled
- ¾ cup (155g) light brown sugar packed
- 1 large egg room temperature
- 1 egg yolk room temperature
- 1 teaspoon pure vanilla extract
- ½ cup (120g) Biscoff spread
- 1½ cups (180g) all-purpose flour spooned and leveled
- ½ teaspoon baking soda
- ¼ teaspoon salt
- 8 Biscoff cookies roughly crushed
Biscoff Swirl & Topping
- 3 tablespoons Biscoff spread warmed
- 6 Biscoff cookies Optional
Instructions
- Preheat your oven to 350°F (175°C). Line an 8×8 inch baking pan with parchment paper, leaving an overhang on two sides for easy lifting.
- In a large bowl, whisk together the melted butter and brown sugar until combined and slightly glossy, about 1 minute.
- Add the egg, egg yolk, and vanilla extract and whisk vigorously for another minute until the mixture is smooth and slightly thickened.
- Add the Biscoff spread and whisk until fully incorporated.
- Add the flour, baking soda, and salt to the bowl. Switch to a spatula and fold until just combined - stop as soon as you no longer see streaks of flour. Do not overmix.
- Fold in the roughly crushed Biscoff cookies until evenly distributed through the batter.
- Pour the batter into your prepared pan and spread into an even layer with your spatula.
- Warm the 3 tablespoons of Biscoff spread in the microwave for 15-20 seconds until pourable. Dollop over the top of the batter in small spoonfuls, then use a toothpick or skewer to swirl through the surface. Sprinkle with extra Biscoff cookies if desired.
- Bake for 22-25 minutes, until the edges are golden and set and a toothpick inserted in the center comes out with a few moist crumbs. The center will look slightly underdone - that’s perfect.
- Let the blondies cool in the pan for at least 30 minutes before lifting out and slicing into 16 squares. Cool completely for the cleanest cuts.
Notes
- Don’t overbake. Pull them out when the edges are set and the center still looks slightly underdone - it firms up perfectly as it cools.
- Weigh your flour. 180g is the sweet spot. Too much flour makes dry, crumbly blondies.
- Cool your butter before adding eggs. If it’s too hot it will scramble them.
- Storage: Store in an airtight container at room temperature for up to 4 days, or refrigerate for up to 7 days.
- Freezing: Cut into squares, freeze on a tray until solid, then transfer to a freezer bag. Freeze for up to 3 months. Thaw at room temperature or microwave for 20-30 seconds.
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