These brownie blondies are swirled with fudgy brownie and gooey blondie layers. The best of both worlds - a brownie and blondie in one!

These brownie blondies are a combination of my go-to brown butter brownies (without the brown butter) and a variation of these blondies, and oh my they are good. You get rich, fudgy brownie, gooey blondie, and melted chocolate in every single bite! I mean how could you say no to that?! Though the two layers are separate recipes, they're both so easy to make - all you need are a couple glass bowls, a whisk, and a rubber spatula. I bet if you start now, you'll have a warm tray of these brownie blondies on your kitchen counter in less than an hour!
For more brownie recipes, try Brown Butter Brownies, Olive Oil Brownies (Dairy Free), Red Velvet Brownies, and Chocolate Cherry Brownies.
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Ingredient Notes
- All-Purpose Flour: You'll need a little less than 1 ½ cups of flour for both the brownie and blondie layers.
- Cocoa Powder: I prefer to use dutch-process cocoa powder for a richer chocolate flavor.
- Baking Powder: Add ¼ teaspoon to the blondie batter for the perfect texture and small amount of rise. The brownie layer does not need any leaveners, as it's meant to be ultra dense & fudgy!
- Eggs: You'll need three eggs (2 for the brownie layer and 1 for the blondies layer) at room temperature.
- Brown Sugar: I opted for dark brown sugar in this recipe because the extra molasses content that adds more depth of flavor, but you can use light brown sugar.
- Granulated Sugar: You'll need ¾ cup of granulated sugar for just the brownie layer.
- Chocolate: You'll need some chocolate to melt and add to the brownie batter, and some to mix in both batters as well as add on top for pieces of chocolate studded throughout each bite! I recommend using semi-sweet or bittersweet.
- Unsalted Butter: For both layers, you'll need a total of 13 tablespoon of butter or 1 ½ sticks + 1 tbsp.
See recipe card for full information on ingredients and individual quantities.
Step by Step Instructions
Here are step by step photos and instructions on how to make this brownie blondie recipe! For the full ingredient list and method, see the recipe card at the end of this post.
STEP 1: Make the brownie batter. In a large bowl, add the brown sugar, granulated sugar, chocolate, and butter. Heat the mixture in the microwave in 20 second increments until everything is fully melted. Whisk the mixture until smooth. Add the eggs and vanilla to the butter, sugar, chocolate mixture, and whisk until fully combined. Next, fold in the flour, cocoa powder, and salt until just combined. Lastly, fold in the chopped chocolate.
Set aside as you make the blondie layer.
STEP 2: Make the blondie batter. In a medium bowl, whisk together the flour, baking powder, and salt. Set aside. In a separate bowl, mix together the melted butter and brown sugar until fully combined. Then, mix in the egg and vanilla. Fold the dry ingredients into the wet until just combined. Lastly, fold in the chopped chocolate.
STEP 3: Assemble. Spread about ⅔ of the brownie batter into the prepared pan. (I reserved about 200g for the top)
STEP 4: Bake. Add all of the blondie batter in large dollops on top the brownie layer, then fill in the gaps with the remaining brownie batter. Top with more chocolate and bake!
Recipe FAQs
The best cocoa powder for making brownies is dutch process cocoa powder! Since dutch process is alkalized, it is neutral rather than acidic, and is far richer in flavor than regular cocoa powder.
These brownie blondies will last for about 3-5 days stored in an air-tight container at room temperature. You could also store them in the freezer for about 3 months.
- Parchment paper: Line your 9x9 pan with parchment paper to ensure the brownie blondies do not stick and for easy removal!
- Kitchen scale: You'll need a kitchen scale to weigh all of your ingredients (read why below)!
Baking in Grams
All of the recipes on this blog are carefully developed with gram measurements so you can easily recreate them in your own kitchen with success. Volume measurements are extremely inaccurate and leave room for significant errors. Not all measuring cups are made equally, so your one cup of flour will be different from my one cup of flour. By providing precise measurements in grams (aside from minor ingredients, which are given in tsp/tbsp), you can make these recipes accurately and with less cleanup! All you need is this kitchen scale.
If this still isn't enough to convince you, I have provided volume measurements in the recipe card. If you are interested in understanding the conversions, this is the best conversion chart.
But trust me, once you try baking in grams you'll never turn back!
Happy baking! x
Other brownie & bar recipes you'll love
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📖 Recipe
Brownie Blondies
Ingredients
For the brownie layer:
- 106 g (½ cup) brown sugar
- 150 g (¾ cup) granulated sugar
- 63 g (2 ¼ oz) chocolate, roughly chopped
- 127 g (9 tablespoon) unsalted butter
- 2 eggs, room temp
- 1 teaspoon vanilla
- 90 g (¾ cup) all-purpose flour
- 60 g (¾ cup) dutch process cocoa powder
- ½ teaspoon salt
- 56 g (2 oz) chocolate, roughly chopped
For the blondie layer:
- 80 g (⅔ cup) all-purpose flour
- ¼ teaspoon baking powder
- ¼ teaspoon salt
- 56 g (4 tablespoon) unsalted butter, melted
- 106 g (½ cup) brown sugar
- 1 egg, room temp
- ½ teaspoon vanilla
- 56 g (2 oz) chocolate, roughly chopped
Instructions
For the brownie layer:
- Preheat the oven to 350 degrees F and line a 9x9 inch square pan with parchment paper.
- In a large bowl, add the brown sugar, granulated sugar, chocolate, and butter. Heat the mixture in the microwave in 20 second increments until everything is fully melted. Whisk the mixture until smooth.
- Add the eggs and vanilla to the butter, sugar, chocolate mixture, and whisk until fully combined.
- Next, fold in the flour, cocoa powder, and salt until just combined.
- Lastly, fold in the chopped chocolate.
- Set aside as you make the blondie layer.
For the blondie layer:
- In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
- In a separate bowl, mix together the melted butter and brown sugar until fully combined.
- Then, mix in the egg and vanilla.
- Fold the dry ingredients into the wet until just combined.
- Lastly, fold in the chopped chocolate.
For assembly:
- In the prepared square pan, add about ⅔ of the brownie batter and smooth into an even layer. I reserved about 200g of batter for the top.
- Next, add all of the blondie batter in large dollops on top of the brownie layer.
- Fill in the gaps between the blondie batter with the remaining brownie batter.
- Lastly, top the brownie blondies with more chopped chocolate, if desired.
- Bake for about 30 minutes or until the blondie layer is golden and the brownie layer appears set.
- Allow the brownie blondies to cool completely in the pan before removing.
- Cut into diamonds or squares, top with flaky sea salt, and enjoy!
Grace says
These are amazing!! Would definitely make them again.
Caroline says
These were amazing will be making again😍
Susan says
Made these yesterday and OH WOW they are so good! Will definitely make again!