Cake Batter Blondies with Marshmallow Buttercream

Cake Batter Blondies are chewy, sweet, loaded with sprinkles, and topped with marshmallow buttercream! They start with a cake mix, with a few added ingredients including marshmallows to up the chewy factor! The prettiest blondies you will ever make!

Top these blondies off with my sweet Party Frosting aka Marshmallow Buttercream!

Cake Batter Blondies are the Perfect Party Dessert!

I made these Cake Batter Blondies way back in 2011, but thought they might need a little facelift! I snapped a few new pictures and thought that I’d bring these beauties back up to the top of your newsfeed again!

What’s not to love about a sprinkle filled, buttery bar topped with fluffy marshmallow buttercream frosting? If you’re looking for a party party treat, this is the easy dessert recipe for you!

It All Starts With A Cake Mix!

The beauty of these blondies is they start with a cake mix! I used Funfetti, because SPRINKLES! But you can certainly use any flavor that you would like. If you’re going for that true “cake batter” flavor, I do recommend that you use any version of vanilla.

Starting with a cake mix is definitely a short-cut. You use the dry cake mix as an ingredient, so don’t prepare the cake according to the package directions. Use it as you would any other dry ingredient.

Add Marshmallows!

Adding marshmallows into the batter makes these blondies extra chewy! It’s a pretty simple ingredient to add that really amps up the chewy factor. They kind of melt into the batter as it bakes, like a secret sweet ingredient.

How To Make Cake Batter Blondies

Ingredients For Cake Batter Blondies…

  • 1 box vanilla cake mix. I used Funfetti, but you can get creative with other flavors!
  • Vegetable oil
  • Egg
  • Milk
  • White chocolate chips. If you use a chocolate cake mix you can use chocolate chips instead! Or if white chocolate isn’t your thing you can leave them out!
  • Mini marshmallows to add extra chewiness
Cake Batter Blondies without frosting

Add Frosting…Or Don’t…

If frosting isn’t your thing, you can absolutely leave it off! I made some without and added some extra sprinkles on top instead.

These blondies are very sweet already, so leaving it off is fine, although I am always up for adding frosting when I can.

I do like to press sprinkles into the top, though, as the batter is a bit thick and the tops of these blondies can be a bit lumpy and not as pretty when baked.

Looking For Other Cake Mix Recipes? Try These:



Cake Batter Blondies

  • Author: Shelly
  • Prep Time Prep Time: 10 minutes
  • Cook Time Cook Time: 25 minutes
  • Total Time Total Time: 35 minutes
  • Yield Yield: 16 1x
  • Category Category: Cake Mix Recipe
  • Method Method: Oven
  • Cuisine Cuisine: Dessert


These blondies are the ultimate sweet treat! Loaded with sprinkles and topped with marshmallow frosting, these Cake Batter Blondies are a party treat!



  • 1 box vanilla cake mix (I used Funfetti)
  • 1/4 cup vegetable oil
  • 1 egg
  • 1/2 cup milk
  • 1/2 cup white chocolate chips
  • 1/2 cup mini marshmallows


  1. Preheat oven to 350°F. Coat a 9×9 baking dish with nonstick spray. Set aside.
  2. In the bowl of your stand mixer fitted with the paddle attachment combine the dry cake mix, vegetable oil, egg and milk. Mix on medium low speed until the ingredients are just combined. Batter will be dense.
  3. Stir in your chips and marshmallows until distributed evenly.
  4. Spread into your prepared pan.
  5. Bake for 25 minutes until center is just set.
  6. Allow to cool completely before frosting.


Top this with my Marshmallow Buttercream (aka Perfect Party Frosting). Cut the recipe in half for the perfect amount for these blondies!

Store airtight at room temperature for 3 days.

Nutrition information is for unfrosted blondies.

Nutrition Information:

16.2 g
194.3 mg
7.6 g
26.7 g
2 g
12.9 mg

Keywords: cookies and cups, cake mix recipe, cake batter blondies, blondies recipe, marshmallow frosting, sprinkles

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Hi! I’m Shelly and I’m an addict. Of the buttercream sort. I started this site a few years ago as a way to justify my sugary, buttery obsession with desserts. It has worked out well for me so far, because as it turns out you guys all love sugary, buttery desserts too! It feels good to know you're not alone, doesn’t it?

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Jun 23, 2020 1:44 pm

Oh!! looks so delicious

Dec 18, 2018 11:23 am

When you say 1 cup marshmallow fluff, do you mean a measuring cup or an 8oz. Container???

Jun 3, 2014 10:12 pm

Awesome buttercream recipe! Thanks!

Dec 25, 2013 9:38 am

is a 9×13 pan ok to use?

Jan 17, 2013 7:08 pm

How much frosting does this recipe yield?

Nov 4, 2012 12:55 pm

These are freaking awesomeness! I’ve made this several times and have done it with diff cake mixes too and added other stuff. Thanks for the great recipe. I love your blog it’s my fav! I’ve made a ton of stuff from it.

Oct 7, 2012 10:59 pm

Great recipe’s, going to make Smores Whoopie Pies……

Sep 4, 2012 7:55 pm

Just a quick question – I have been looking for a buttercream recipe that will hold up outdoors for a few hours without refridgeration – I am not too excited about the ones that are shortening based but this one sounds yummy – do you think it will be ok unchilled since there isn’t too much butter?

lenora scott
Sep 4, 2012 11:34 am

Yes those sausages are pretty bad but we keep them in our emergency cupboard, having lived in a hurricane prone environment. Can’t wait to try the icing.

May 15, 2012 9:51 am

Hey babe! Glad you like the Cake Batter Blondies 🙂 I hate to be a pain, but would you mind linking my post as well? I’m almost positive the originate back to my post 🙂 Thanks so much, I really do appreciate it!

Apr 28, 2012 10:28 pm

I just cried a little. ='( I found your s’mores whoopie pies from Pinterest and thought they would be PERFECT for my daughter’s indoor campout birthday party. So then I mosey on over to this page to find out how to make the marshmallow buttercream and find out it requires Fluff! They don’t sell Fluff down here in San Antonio – just marshmallow cream (not the same consistency)! PLEASE tell me marshmallow cream is an acceptable substitute!

Mar 5, 2012 3:16 pm

Ha! You had me at hello! Loved the story and can’t wait to try the recipe. 🙂

Sep 28, 2011 2:14 pm

Shelly! You are da bomb! I’m a Texas (San Antonio, though) gal too and I just found your recipe for pumpkin dump cake on Pinterest and thought yum and that I could actually make that without struggle. Then I stumbled upon your Candy Corn Bugle Blog and I about died laughing, I had to call my sister and read it to her…me being the person that gets dragged to exercises that kill me, her being the one doing the dragging! I know we just met but I can tell you are going to be one of my new besties in… Read more »

April Grunewald
Sep 11, 2011 9:32 pm

Omg!! I love your cake stand. Can you share where you purchased? Thanks!!

Sep 10, 2011 9:41 pm

i’ll admit it–i loved those vienna sausages. i called them meat sticks, which now sounds really gross.
great bars, by the way–i love the coloring!

Shelly Hi! I’m Shelly and I’m an addict. Of the buttercream sort. I started this site a few years ago as a way to justify my sugary, buttery obsession with desserts. It has worked out well for me so far, because as it turns out you guys all love sugary, buttery desserts too! It feels good to know you're not alone, doesn’t it?

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