Brownies are what I'm known for here on Scientifically Sweet (check out my very popular Perfect Shiny Crust Brownies and BEST Homemade Thick Brownies), but blondies have their space too. These Dark Chocolate Hazelnut Brown Butter Blondies are so ooey gooey, moist and fudgy with so much rich flavor. They will certainly be the best blondies you have ever made, and I'm confident about that. These blondies are made with white chocolate (not just butter and brown sugar), so you get the rich milky notes from the white chocolate that add way more depth and complexity to these wonderful squares. If you love brownies, I can recommend my White Chocolate Raspberry Blondies and Lemon Brownies which are also dangerously good!

WHY YOU WILL LOVE THIS RECIPE
- Fast & easy to make - these blondies come together quickly and take less than 30 minutes to bake.
- Moist gooey texture - mixing the eggs with the right amount of sugar ensures that these blondies are moist, gooey and fudgy.
- Rich brown butter flavor - brown butter adds complex nutty, caramel flavors to this recipe that takes it over the top. The extra egg yolk also contributes to the rich custardy flavor. The combination of brown butter, hazelnuts and chocolate is so complementary!
- Chocolate chunks, not chips - for the best texture and most dramatic pools of chocolate, I recommend dark chocolate chunks chopped from a chocolate bar. These chunks will melt evenly into the batter whereas chocolate chips will hold their shape.
- Dark chocolate - I definitely recommend dark chocolate with around 60% cocoa solids or higher for this recipe. It will balance the sweetness.
- Toasted hazelnut blondies - definitely toast your nuts! It is well worth the time and effort in this recipe. Roasted hazelnuts taste so much more than raw hazelnuts.

INGREDIENTS FOR HAZELNUT BROWN BUTTER BLONDIES
Here are some notes about the ingredients. For a full list of ingredients, check out the recipe card at the bottom of the page.
- Unsalted butter - there is no substitute for butter in a blondie recipe in my opinion! It is the foundation of the rich butterscotch flavor. In this recipe, you will brown the butter which is a technique common in French cooking called "beurre noisette". It translates to "hazelnut butter" since the butter actually takes on nutty flavors once it is browned. Don't worry - it's easy! You just cook the butter gently until all of the moisture boils off an the milk solids toast up.
- All purpose flour - regular all purpose flour is perfect to make fudgy and chewy blondies. Use unbleached flour which will give you that nice dense texture.
- Pure vanilla extract - vanilla is essential to this recipe since it is the main flavor that complements the rich buttery notes and sweet dairy notes. I like this Madagascar vanilla extract.
- Eggs - two whole eggs will set the structure of these brownies for a gooey fudgy custardy texture without tasting or smelling "eggy".


- Granulated sugar - simple fine white granulated sugar keeps these blondies moist. If you reduce the sugar they will not be as fudgy and they are less likely to have the shiny crust.
- Brown sugar - you can use light or dark brown sugar in this recipe. Although I adore dark brown sugar, the molasses can overtake the taste of the brown butter so I prefer light brown sugar for this recipe.
- Egg - 2 whole eggs will provide majority of the structure in these blondies.
- White chocolate – pure white chocolate adds sweet milky creaminess and the milk proteins in the milk powder will contribute to the browning (technically known as "Maillard Browning" - a delicious natural chemical food reaction) to add color and flavor.
- Hazelnuts – you should definitely toast or roast your nuts for this recipe which will completely transform the flavor. The quickest way is to place them in a dry frying pan over medium heat until they darken in color and smell fragrant. You can also roast them at 350 degrees F for about 10 minutes until fragrant.
- Dark chocolate chunks - this is important! I highly recommend using bar chocolate, that is, chunks that you chop up from a bar of chocolate instead of chocolate chips. Why? That is because chocolate that is made into bars, also known as "tablets" has a higher cocoa butter content and typically melts smoother than chocolate chips to give you puddles of chocolate. I love this effect! Chocolate chips will hold their shape and spread less.

STEP BY STEP INSTRUCTIONS
- STEP 1). Make brown butter. First melt the butter over medium-low heat in a saucepan. Continue cooking, letting it boil gently and crackle. Once all of the moisture boils off, a dense foam will begin to appear at the surface and it will start to smell nutty as the milk solids brown. Stir the butter constantly. When the foam subsides and you see the golden brown bits, it is ready.
- STEP 2). Cool the butter. Immediately pour it off into a clean bowl. You should be left with golden yellow liquid butter and lots of nutty brown flecks. Let it cool for about 5 minutes so it is no longer piping hot.
- STEP 3). Melt chocolate. Add the chocolate to the bowl with the hot browned butter and stir until melted and smooth.
- STEP 4). Beat eggs with sugar. Combine eggs with both sugars in a large bowl and use a whisk to beat until pale, thick and fluffy. Mix in salt.

- STEP 5). Add melted chocolate. Mix warm white chocolate mixture into the egg mixture until evenly blended.
- STEP 6). Add flour. Sprinkle flour over the batter and fold it in gently until well incorporated and smooth.
- STEP 7). Fold in chocolate and hazelnuts. Add the chocolate chunks and hazelnuts and fold them through.
- STEP 8). Bake. Spread the batter evenly into prepared pan and sprinkle a few extra chocolate chunks and hazelnuts on top. Bake for 23-26 minutes until evenly golden but still soft in the middle!

WHAT IS BROWN BUTTER?
Butter is technically an emulsion (a water-in-oil emulsion to be exact) made up of milk fat with tiny droplets of water suspended throughout. The water portion contains milk proteins and trace amounts of milk sugars (lactose). When heated to a certain degree, these milk proteins and milk sugars react in a process called "Maillard Browning" to create nutty and caramel-like flavor compounds as well as generate brown color compounds.
This process occurs when there is no moisture present, which is why you need to cook butter until the water content is evaporated off in order to make brown butter. Once you make brown butter, you are left with essentially pure oil.

HOW TO MAKE BROWN BUTTER
If you've never made brown butter, you MUST try it. It adds amazing complexity and richness in the form of nutty, caramel-like flavors that enhances many recipes.
- STEP 1). First melt your butter over medium heat in a small sauce pan. Make sure to use a stainless steel saucepan so you can see what's happening. If you use a dark pan it may be difficult to monitor the change in color.
- STEP 2). Once melted, let the butter come to a simmer. It will crackly as it boils. This is the sound of the water content (approximately 15%) evaporating out. Stir the butter constantly as it melts to ensure it cooks evenly and so the brown bits don't catch at the bottom. Stirring will bring them up to the surface above the foam so you can watch the color change.
- STEP 3). As the moisture evaporates, the butter will start to foam. This is the point when the browning starts to happen. Keep stirring the butter. Keep a close eye on the butter and DO NOT WALK AWAY.
- STEP 4). Eventually the crackling will settle down and the foam on the surface will become very dense to the point that you cannot see the clear butterfat beneath it. The foam will turn golden and as you stir you should see little brown flecks coming up into the pan. This is the sign that you are done! The butter will turn a golden color and you’ll know it’s done by the smell... it will have a toasted, caramelized and nutty aroma.
- STEP 5). Immediately pour it out into a clean bowl and let it cool before using it in the recipe.
EXPERT BAKING TIPS
- Be sure to not over-bake the blondies or they can end up more dry instead of dense and fudgy.
- Let the finished blondies cool completely for at least 2 hours before slicing to ensure you get those nice clean slices.
- Roast the hazelnuts for the most flavor.

RECIPE FAQ
White chocolate is so important for this recipe to create the fudgy texture and to make the shiny crust. Do not leave it out.
Make sure you use pure white chocolate. Do not use compound chocolate which contains other vegetable oils. White chocolate should contain pure cocoa butter which will give these brownies a fudgy texture. If you use compound chocolate, then they may feel greasy and they may not bake properly.
I love this combination of roasted hazelnuts and chocolate, but you can also use pecans, walnuts or macadamia nuts. I would avoid using almonds which have a harder texture.
The trick to making clean slices for blondies is to let them cool completely. If you really want a perfect edge, chill them thoroughly and then use a hot dry knife. Dip the knife in hot water and then wipe it clean and dry between each slice.
These blondies will keep at room temperature in an airtight container for up to 5 days.
If you love brownies, check out these recipes!
Peanut Butter Fudge Swirl Brownie Bottom CheesecakeBetter Than Box Brownie Mix RecipeThe BEST Small Batch Fudge BrowniesBuckeye Peanut Butter Fudge BrowniesBEST Fudgy Brownie Recipe with Shiny CrustThe BEST Fudgy Flourless Brownie CookiesBars & Squares
Looking for other squares and bars like this? Try these:
Baking with brown butter...
Do you love baking with brown butter? Check out these recipes:
Dark Chocolate Hazelnut Brown Butter Blondies
Ingredients
- 3 oz 85g white chocolate, coarsely chopped
- 7 tablespoon 100g salted butter, browned (see instructions below and also above in the article)
- 2 large eggs, at room temperature
- ½ cup 110g packed light brown sugar
- ¼ cup 50g granulated sugar
- 1 teaspoon 5ml pure vanilla extract
- ¼ teaspoon salt
- 1 cup 142g all-purpose flour
- 1 cup 142g dark chocolate chunks
- ½ cup 70g chopped roasted hazelnuts
Instructions
- Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper leaving a 2-inch overhang along each side.
- Brown the butter. Melt it over medium heat in a small saucepan. Make sure to use a stainless steel saucepan so you can see what's happening. If you use a dark pan it may be difficult to monitor the change in color. Once melted, let the butter come to a simmer. It will crackly as it boils. Stir the butter constantly as it melts to ensure it cooks evenly and so the brown bits don't catch at the bottom. As the moisture evaporates, the butter will start to foam and eventually the crackling will settle down and the foam on the surface will become very dense and it will turn golden. As you stir you should see little brown flecks coming up into the pan, the butter will turn a golden color and it will have a toasted, caramelized and nutty aroma.
- Immediately pour the browned butter into a clean bowl and let it cool for 5 minutes so it is not boiling hot, then add the chopped white chocolate. Stir until the chocolate is completely melted and the mixture is smooth. Set it aside. It does not need to be completely cooled to use in the recipe.
- Make the blondie batter. Combine eggs with both sugars and vanilla in a large mixing bowl and whisk vigorously until pale and thick. It should double in volume. You can also use a hand mixer for this step. Mix in salt. Sprinkle in the flour and fold it in gently. Add dark chocolate chunks and chopped roasted hazelnuts and fold them in evenly.
- Spread batter evenly into your prepared pan. Sprinkle a few extra chocolate chunks and hazelnuts over top and then bake for 23-26 minutes until the top is shiny, golden and crackly and the center is still soft. Do not over bake these. Transfer pan to a wire rack and let the blondies cool completely before slicing. Enjoy with a glass of cold milk!
Sophie
This combination of ingredients is truly incredible. My dad doesn't even like desserts and he said I need to make them again. Thanks!
Amanda
Just... WOW! I've never been much of a blondie person, but this recipe looked too good. I'm so glad I tried it because now I think I've found my new favorite thing to bake.
Penny
I made these after seeing them on IG and holy cowwwww - amazing! They are very very very good.
Mary
These are the best ever! That’s all!
NEHA
Superb recipe. Loved it so much
John Lizotte
This recipe makes no sense in the baking tips it says to coat your raspberries in flour? Huh? Theres no raspberries in the recipe!!
Jane Gundlach
Does anyone seriously need or read the long winded preamble before they get to the recipe. I would absolutely noy even consider making this uf I had to read through all that nonsense first. As a baker all I need is the recipe but if I wasn't that overload if vet age before the recipe would certain scare me off. I have made some trust complicated French recipes that didn't go into this much detail. These are just a bar cookie, a brownie! Ridiculous.
Leslie Phillips
These sound amazing and I’m definitely making them soon but a quick question: you melt the white chocolate but not the dark chocolate?