This funfetti blondies recipe features deliciously chewy brown sugar and vanilla-laced cake batter-flavored cookie bars. Fun, festive rainbow sprinkles and a creamy vanilla frosting take it over the top!
Blondies are a deliciously fun treat even when they’re not funfetti flavor. But when you make them cake batter flavor and add colorful rainbow sprinkles, it’s really a party!
Once you master the basic method for making blondies you’ll see how quick and easy they are. Without the frosting, these whip up in about 30 minutes including bake time with just one bowl and no need for a stand mixer.
And you’ll think of a ton of different ways to customize them because the sky is the limit! Dark chocolate chips, white chocolate chips, chopped nuts, dried fruit, etc. It all works.
Like other bar cookies, these are the perfect treat for potlucks and parties. And funfetti blondies can also make a stand as birthday cake blondies, which makes them perfect for birthday celebrations. But don’t wait until then to make them!
Blondies are the perfect treat on a random Tuesday evening when you want something a sweet without having to spend hours in the kitchen. And funfetti makes them fun!
Why You’ll Love This Recipe
- They’re delicious. Rich and chewy buttery brown sugar blondies are made fun and colorful with rainbow sprinkles! Sweet vanilla buttercream is optional, but makes them decadent.
- Happy birthday. Funfetti blondies are great for a birthday celebration. Like any funfetti, cake batter-flavored treat, this is the perfect birthday dessert!
- Dessert doesn’t get any easier. However, unlike baking up a funfetti birthday cake, blondies are much quicker and easier to make!
The Best Funfetti Blondies Recipe
Ingredients
Funfetti Blondies:
- Unsalted butter
- Granulated sugar
- Light brown sugar
- Egg
- Vanilla
- Cake batter flavor
- All-purpose flour
- Salt
- Rainbow sprinkles
Vanilla Frosting:
- Unsalted butter
- Powdered sugar
- Heavy whipping cream
- Vanilla
- Salt
Step-by-Step Instructions
Step 1: Make the Funfetti Blondies:
Preheat the oven to 350F. Line an 8 by 8-inch baking pan with 2 pieces of parchment paper so it hangs over all 4 sides.
Melt the butter in a large bowl in the microwave and let it cool for about 30 seconds to 1 minute. Whisk in the granulated sugar and brown sugar until well-mixed. Whisk in the egg, vanilla extract, and cake batter flavor. Add the flour and salt and stir until combined, being careful not to over-mix. Fold in rainbow sprinkles.
Pour the batter into the prepared pan. Bake until the outside looks light golden, but the inside looks doughy, about 22 to 25 minutes. Let the blondies cool for about 10 minutes in the pan, and then remove them to a wire rack to cool to room temperature.
Step 2: Make the Vanilla Frosting:
While the blondies are cooling, make the frosting.
Add all ingredients to a large bowl. Use a handheld electric mixer to beat until well-combined. You may need to add a bit more heavy whipping cream to achieve the right consistency.
Step 3: Frost the Blondies:
Frost the blondies once they’re cooled. Before the frosting sets, top with more rainbow sprinkles.
How to Store Blondies
Wrap your blondies well, and then store them for up to 4 days at room temperature or up to 1 week in the fridge.
Tips
- The butter should still be hot. After you melt the butter, only let it cool for about 30 seconds to 1 minute before whisking in the sugar. This will help make sure you get a gorgeous crackled top!
- Instead of cake batter flavoring. If you can’t find cake batter flavor, you can substitute with a combination of butter flavor and almond extract. (About 1/2 teaspoon butter flavor and 1/8 teaspoon almond extract for this recipe.)
- Don’t bake blondies until the center is set. They’re done when they still look a touch doughy in the center because they will continue cooking in the pan.
- The frosting is optional. Yes, the frosting is delicious and it whips up in just minutes. And yes, it completes the birthday cake look. But it really is gilding the lily; these blondies are amazing even without frosting!
Blondies FAQs
What is a Bar Cookie?
A bar cookie is essentially made from cookie dough that’s pressed into a pan, baked, and then cut into bars.
Bar cookies taste similar to regular cookies. However, the texture is quite a bit different; bar cookies are a bit chewier and gooier than regular cookies.
This is because bar cookies are baked as one big unit and then cut. As a result, only the bar cookies that are cut from the outside have a crispy edge.
How Do I Know When Blondies Are Done?
Blondies are done when the outer edge is light golden brown. The dough should look set along the outer inch or so of the pan, but it should still look doughy in the center.
Your blondies will continue cooking in the hot pan even after you take them out of the oven. If you let them bake until they don’t look doughy in the center, they will be dry and not gooey.
I don’t recommend a toothpick test for blondies because if the toothpick comes out dry, your blondies will be overcooked!
How Are Blondies Different Than Cake?
Blondies are much denser and chewier than cake. Cake is typically light and fluffy because of a leavening agent, such as baking powder or baking soda. On the other hand, blondies don’t typically contain a leavening agent like that.
Blondies are meant to be dense and moist instead of light and fluffy.
More Blondies Recipes to Make
Let’s Connect
I love hearing from you!
Did you make this recipe? Please rate it and leave a comment.
You can also tag @anediblemosaic on social media.
To stay up-to-date, follow me on Facebook, Instagram, Pinterest, and Twitter!
xoxo, Faith
Funfetti Blondies (Rainbow Sprinkle Birthday Cake Batter Blondies with Vanilla Frosting)
Ingredients
Funfetti Blondies:
- 10 tablespoons unsalted butter melted and cooled slightly
- 1/2 cup granulated sugar
- 1/4 cup light brown sugar lightly packed
- 1 large egg
- 1 1/2 teaspoons pure vanilla extract
- 1/2 teaspoon cake batter flavor see Notes
- 1 cup all-purpose flour
- 1/4 teaspoon salt
- 5 tablespoons rainbow sprinkles divided
Vanilla Frosting:
- 2/3 cup unsalted butter at room temperature
- 2 cups powdered sugar sifted
- 5 teaspoons heavy whipping cream or more as needed
- 1 teaspoon pure vanilla extract
- 1/8 teaspoon salt
Instructions
For the Funfetti Blondies:
- Preheat the oven to 350F. Line an 8 by 8-inch baking pan with 2 pieces of parchment paper so it hangs over all 4 sides.
- Melt the butter in a large bowl in the microwave and let it cool for about 30 seconds to 1 minute. Whisk in the granulated sugar and brown sugar until well-mixed. Whisk in the egg, vanilla extract, and cake batter flavor. Add the flour and salt and stir until combined, being careful not to over-mix. Fold in 4 tablespoons rainbow sprinkles (reserving 1 tablespoon for decorating the top).
- Pour the batter into the prepared pan. Bake until the outside looks light golden, but the inside looks doughy, about 22 to 25 minutes. Let the blondies cool for about 10 minutes in the pan, and then remove them to a wire rack to cool to room temperature.
For the Vanilla Frosting:
- While the blondies are cooling, make the frosting.
- Add all ingredients to a large bowl. Use a handheld electric mixer to beat until well-combined. You may need to add a bit more heavy whipping cream to achieve the right consistency.
To Frost the Blondies:
- Frost the blondies once they’re cooled. Before the frosting sets, top with the remaining 1 tablespoon rainbow sprinkles.
Faith’s Tips
- Don’t Let the Butter Cool Too Much: After you melt the butter, only let it cool for about 30 seconds to 1 minute before whisking in the sugar. This will help make sure you get a gorgeous crackled top!
- Cake Batter Flavoring Substitute: If you can’t find cake batter flavor, you can substitute with a combination of butter flavor and almond extract. (About 1/2 teaspoon butter flavor and 1/8 teaspoon almond extract for this recipe.)
- Don’t Overbake: Blondies are done when they still look a touch doughy in the center because they will continue cooking in the pan.
- Storage: Wrap your blondies well, and then store them for up to 4 days at room temperature or up to 1 week in the fridge.
- Frosting Optional: Yes, the frosting is delicious and it whips up in just minutes. And yes, it completes the birthday cake look. But it really is gilding the lily; these blondies are amazing even without frosting!
Nutrition
I’m Faith Gorsky, the writer, cook, and photographer behind An Edible Mosaic. My goal is to inspire you to get in the kitchen and try something new! Feel free to 
Can this recipe be doubled and put into a 9×13 inch pan?
Heidi, Yes! They need a few more minutes to cook, but you can leave everything else the same.
Can this recipe be doubled and the use cook cutters after for easter shape?
Morgin, Definitely! That would be adorable :)
everything’s more fun with sprinkles! :)
I would love those for my birthday! They look delicious,Faith!
I love giving baked goods as presents…solves so many problems and everyone wins because usually you get to taste whatever you make. :) The funfetti infusion of these is fabulous!
My co-workers love treats of any kind, whether it’s for a birthday or not. They’d love these! :)
Just starting to like blondies! Shocking I know. These look great.
I love funfetti and blondies and cake batter-flavored things! So um, yeah, this is going on the “make-this-right-now” list! :)
These are the cutest; love the sprinkles!
My old roommate and I used to love making funfetti cakes, so these bring back great memories. My birthday is on Wednesday, so I may just have to whip up a batch of these for myself. ;)
These are definitely a perfect gift! Cute and yummy? Winning! Love the sprinkles throughout
Pretty and totally irresistible!
Cheers,
Rosa