Fruity Pebbles Whoopie Pies are a playful and fruity spin on a classic dessert. Marshmallow buttercream and Fruity Pebbles “sprinkles” make them irresistible.
This post is sponsored by Post Foods®. All opinions are my own. Thank you for continuing to sponsor the brands that make My Baking Addiction possible.
If you’re a regular reader, you know that my husband is pretty much the pickiest eater that I’ve ever encountered. He’s not super keen on sweets (crazy, right?) and most vegetables are a no-go.
However, there is one thing that he eats every single day, and that thing is cereal. Even if we’re staying at a hotel, he heads to the nearest store to pick up a box of Cocoa Pebbles and a half gallon of milk. He’s that serious about his nightly cereal ritual.
In fact, there are no less than six boxes of cereal and two gallons of milk in our refrigerator at any given time.
Needless to say, when I was contacted by Post Foods to create and share a recipe with their Pebbles cereals, he was pretty excited – especially when I told him a big box full of Cocoa Pebbles and Fruity Pebbles landed on our doorstop. Seriously, best mail day – ever!
Although I’ve loved Fruity Pebbles since I was a kid, I hadn’t created a dessert with them aside from marshmallow cereal bars, so I was excited to get into the kitchen and create a playful, fruity, and fun dessert.
I jotted down so many ideas from donuts and cookies to ice cream cake, but ultimately decided on these Fruity Pebbles Whoopie Pies.
I mean what could possibly bring out your inner-child more than a two soft cookies sandwiched together with marshmallow buttercream and rolled in Fruity Pebbles?
These Fruity Pebbles Whoopie Pies start with soft, cake-like cookies with loads of Fruity Pebbles in the batter. They’re sandwiched together with a super simple, dreamy marshmallow buttercream and then rolled into more Fruity Pebbles – because more is always more when it comes to Fruity Pebbles.
I hope these Fruity Pebbles Whoopie Pies inspire you to think outside the box (see what I did there?) and create a delicious treat that your family is sure to love.
For more inspiring Pebbles ideas and recipes, be sure to connect with them on Facebook

Fruity Pebbles Whoopie Pies
Fruity Pebbles Whoopie Pies are a playful and fruity spin on a classic dessert. Marshmallow buttercream and Fruity Pebbles “sprinkles” make them irresistible.
Ingredients
For the Whoopie Pies:
- 1/2 cup butter flavored shortening
- 1 cup granulated sugar
- 1 egg
- 2 teaspoons vanilla extract
- 1/2 cup buttermilk
- 1/2 cup hot water
- 2 1/2 cups all-purpose flour
- 1 1/2 teaspoons baking soda
- 1/2 teaspoon salt
- 1 cup Fruity Pebbles, lightly crushed
For the Marshmallow Buttercream:
- 3/4 cup unsalted butter, room temperature
- 1 1/4 cups powdered sugar, sifted
- 2 teaspoons vanilla extract
- 1 7-ounce container marshmallow cream
For the Garnish
- 1/2 cup Fruity Pebbles, lightly crushed
Instructions
For the Whoopie Pies:
- Preheat the oven to 400°F. Line baking sheets with parchment paper.
- In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with an electric mixer, cream together the shortening and sugar until light and fluffy.
- Add in the egg, vanilla, buttermilk, and water and mix until the ingredients are fully incorporated.
- In a medium bowl, whisk together the flour, baking soda and salt. Slowly add the dry ingredients to the shortening mixture and mix until just combined. Use a rubber spatula to gently fold the Fruity Pebbles into the batter.
- Use a medium cookie scoop (1.5 tablespoons) to drop batter onto prepared cookie sheets about 2 inches apart.
- Bake for 8-9 minutes in the preheated oven.
- Allow cakes to cool on baking sheets for 5 minutes before removing to wire racks to cool completely.
For the Marshmallow Buttercream:
- In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on medium-high speed for 3-4 minutes.
- Turn the mixer down to low speed and gradually add in the powdered sugar until thoroughly combined. Turn the mixer back up to medium-high speed and mix for 5 minutes.
- Add in the vanilla extract and marshmallow cream and beat an additional 2 minutes.
To Assemble the Whoopie Pies:
- Spoon or pipe the buttercream onto the flat sides of half the cakes and top with remaining cakes.
- Roll the sides of the whoopie pies into Fruity Pebbles to garnish
Notes
- The marshmallow buttercream will generously fill 16-18 whoopie pies. If you prefer less filling, I would recommend cutting the recipe in half.
- To lightly crush the Fruity Pebbles, place them into a ziptop and gently crush the cereal pieces with your hands.
Marijka Lombardi
Wednesday 26th of June 2019
What if I don’t have a stand mixer, will a regular mixer work?
Jamie
Wednesday 10th of July 2019
Hello! Yes, a hand mixer will work fine. Happy baking! Jamie
Jen
Wednesday 1st of August 2018
Can you use butter instead of shortening??
Jamie
Wednesday 1st of August 2018
Jen- Hello! I haven't attempted this recipe with butter, so I am not sure of the result. If you happen to give it a try, I'd love to know how they turned out. Thanks so much for stopping by. -Jamie
Heather
Friday 6th of July 2018
A local bakery makes these, and my girlfriend loves them. The bad part? They only have them once in a blue moon. Now I can make them whenever she wants (like today, which is her birthday!)
One quick question...Do you think I could substitute real butter instead of shortening? She usually likes chewier cookies, so I thought that might be one way to get the texture.
Jamie
Wednesday 8th of August 2018
Hello! I haven't attempted this recipe with this substitution, so I am not sure of the result. If you happen to give it a try, I'd love to know how they turned out. Thanks so much for stopping by. -Jamie
Alita
Thursday 1st of June 2017
Can regular shortening be used instead of butter flavored ?
Jamie
Saturday 3rd of June 2017
Hi, Alita! I haven't tried regular shortening in this recipe, but I think you could. Let me know how you enjoy it!
Miranda
Sunday 18th of September 2016
These are such a fun idea! I love how colorful they are!
Jamie
Tuesday 20th of September 2016
Thank you so much, Miranda!