Dark Chocolate Hazelnut Brown Butter Blondies

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 blondies, I can recommend my White Chocolate Raspberry Blondies and Salted Espresso Chocolate Chunk Blondies which are also dangerously good!

WHY THIS RECIPE WORKS

• 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.

• Salted 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. The instructions for how to brown butter are here.
• 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. Melt butter 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.
• 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 2 minutes so it is no longer piping hot.
• STEP 3). Melt chocolate. Add the white chocolate to the bowl with the hot browned butter and stir until melted and smooth, then set aside.
• 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 the 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

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Video

Dark Chocolate Hazelnut Brown Butter Blondies

Christina Marsigliese

Fudgy, moist, ooey gooey Brown Butter Blondies with roasted hazelnuts and dark chocolate chunks. These delicious blondies are made with pure white chocolate and have so much rich caramelized flavor.

4.88 from 16 votes

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 25 minutes mins

Servings 16 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
• heaped 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.
• First brown the butter. Follow the instructions in this post here to learn how to brown butter. It's easy!
• Immediately pour the browned butter into a clean bowl and let it cool for 2 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 and then mix in the melted white chocolate mixture. 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!