Last updated on February 13th, 2026.
Brownie blondies are swirled dessert bars that blends the rich, fudgy texture of a brownie with the sweet, buttery flavor of a blondie. It’s chewy, gooey treat with a delicious contrast of brownie and blondie.
The best way I can think of describing brownie blondies bars is the Classic Marble cake. Just like marble cake has some vanilla batter and some chocolate batter, this recipe has some brownie batter in it and some blondie batter in it.And in every bite, you get to enjoy both worlds. Its tender, buttery and gooey but in a good way.
This is one of those easy, simple, no mixer, and unique recipes you can make last minute, or with your kids as a family activity. And my favorite part is that it is a huge crowd pleaser. It is my go to part contribution (along with these Butterscotch Blondies).
Key Ingredients in this recipe
Full measurement and instructions for the Brownie blondies you can find below on the recipe card.
- Unsalted butter. The butter is critical for this recipe because it sets the moist, tender texture of the batter, so it is important to use high quality unsalted butter. If you wish to use salted butter, remove the salt from the recipe. For dairy free option, use vegan butter.
- Unsweetened natural cocoa powder. For the brownie recipe only, and its the best way to add deep chocolate flavor and give the batter a rich, dense brownie texture. You can use dark chocolate, but please make sure it is 80% chocolate or up.
- Brown sugar. Brown sugar has molasses in it, so it increases the deep butterscotch like flavors of the recipe and it helps maintain the moist texture of the recipe.
- Eggs and egg yolk. Room temperature eggs and egg yolk add richness and help bind the ingredients together, giving the blondies their chewy, fudgy texture.
Flavor Variations
- Add 1/2 cup of chocolate chips, or chopped nuts.
- Brown butter. Use brown butter for chewy blondies with a nutty flavor in the blonde batter. Make sure to mix in 1 tbsp of milk to compensate for the loss of water in the butter.
- For an intense chocolate flavor, add 1 tsp of espresso powder or instant powder to the brownie mix.
Make It
You only need two large bowls, and a whisk or a wooden spoon to make the recipe.
Make The Brownie batter
- In a large bowl, melt the chopped chocolate and butter.
- Mix in the sugar then mix in the egg and vanilla extract. Mix the eggs until you have a smooth mixture, if not incorporated well the bars will bake greasy.
- Add the flour and salt and use a wooden spoon to blend the flour mixture into the wet ingredients at low speed. Fold in the chocolate chips or nuts halfway into the mixing.
- Pour the batter into a prepared 8”x8” square baking pan lined with parchment paper.
Make The Blondie Batter And Assembling
- In a medium bowl, mix the butter and sugar together then add the egg and vanilla extract.
- Add the dry ingredients and gently mix them into the batter.
- Pour the batter into the prepared pan, over the brownie batter, and use the back of a knife to gently mix the two, once or twice. Do not overdo it or the two will bind together and you will have just bars instead of brownie blondie bars.
Expert tips and troubleshooting
As I was testing the recipe I learned that the key to the success of this recipe is accuracy.
- If possible, invest in a high quality kitchen scale. I believe that this is the most important tool for any baker, even more so than a stand mixer.
- The cookies are ready when a cake tester comes out dry with some moist crumbs around them. The top should be golden brown.
- Allow the cookies to cool completely in the pan before removing them. There is no need to use a wire rack, they will break if removing too soon.
- When I added not enough flour or too much butter, the blonde batter came out too thin and did not set. I was not even able to lift it, it just laid there on the cutting board.
- When I added too much flour (intentionally or by mistake) the bars came out too cakey, with a dense unpleasant texture.
Yields & Storing
This recipe yields one 8×8 square pan, about 12-16 pieces, depending on the size of the slices. When baking for a crowd, double the recipe and use 9×13-inch pan.
Best to store the cookies at room temperature in an airtight container for up to 3 days.
You can freeze them for up to 4 weeks. Wrap in a plastic wrap, then place in a freeze bag or wrap in aluminum foil or a freezer bag and freeze. When ready, unwrap and allow to reach room temperature on your kitchen counter.
Brownie Blondies
Equipment
- 1 8"x8" squate pan
- 1 pieces of parchment paper
- 2 medium bowls
- rubber spatual
- hand whisk
Ingredients
Brownie batter
- 6 TBSP Unsalted butter (85 g / 3 oz)
- 1/2 cup Unsweetened chocolate, chopped (85 g / 3 oz)
- 1/2 cup Dark brown sugar (100 g / 3.5 oz)
- 1 Large Egg
- 1 Large Egg yolk
- 1/2 Cup All purpose flour (60 g / 2 oz)
- 1/4 tsp Salt
Blondie batter
- 1/2 Cup Unsalted butter,melted (113 g / 4 oz)
- 3/4 Cup Light brown sugar (150 g / 5 oz)
- 1 Large Egg
- 1 teaspoon Vanilla extract
- 1/2 Cup All-purpose flour (60 g / 3 oz)
- 1/4 tsp Salt
Instructions
Brownie
- Preheat oven to 350F and line 8"x8" square pan with parchment paper.
- Place the butter and chopped chocolate in a medium bowl and melt together. You can use the microwave or a double broiler.
Add the sugar and mix until incorporated then mix in the egg and egg yolk. Set aside while you make the blondie batter.- Fold in the flour and salt and mix until fully blended.
Blondie
- In a medium bowl, mix the melted butter, vanilla extract, and sugar then mix in the egg.
- Fold in the flour and salt. (at this stage you can fold the flour into the brownie batter)
Assemble
- Pour the brownie batter into the prepared pan then the blondie batter.
- Use a knife to create a few swirls hen bake for 22 minutes. The blondies are ready when a toothpick comes out with a few moist crumbs from the center.
- Remove from the oven and alow to completely cool before inverting and slicing.
Made them yesterday because I really needed something sweet and this recipe was perfect. The brownies are very buttery and delicious. Adding it to my favorites.
Thank you, Sharon; so glad you enjoyed it!
Hi, is it okay to prepare and chill the batter for a couple of days before baking?
Couple of days might be too long. You can bake them freeze for a few days.
I think there might be something wrong with the recipe for the blondie brownie. For the blondie it’s too runny and there is no vanilla extract in the recipe but you say there is vanilla extract earlier (and it is pictured). Maybe you need 1 cup for flour for the 1/2 cup of butter?
The blondie may seem runny when first out of the oven, you can bake it extra 5 minutes. The measurements are correct, more flour will give the blondie a cake texture.
but you didn’t answer or correct the vanilla issue…
Mix it with the melted butter and egg when making the blondies.