Make These Adorable Rainbow Cupcakes Super Quick!

I love how fun these Rainbow Cupcakes turned out–but the best part is that the kid wanted a unicorn party and we made these in just a few minutes!

how to make rainbow cupcakes with cloud frosting
Make these easy rainbow cupcakes for the best rainbow party by the pool this summer!

Rainbow Cupcakes

Here at Ruffles and Rain Boots, we love making use of rainy days and throwing parties for no reason–well, my kiddo does anyway. So, when she insisted on a mini unicorn party with rainbow cupcakes (why it wasn’t a rainbow party, I have no idea) we were in the kitchen, hustling. Surprisingly quickly, we had a cupcake with a rainbow on top!


And how fun it was–the kiddo did all the heavy lifting, even mixing a little and putting together the rainbows. If you’re ready to make a rainbow cupcake you’re going to love, let’s get started.

easy rainbow cupcake recipe with cloud frosting
No Time to Make This Now? Pin it for Later

You’re busy, I get it. Pin this to your favorite unicorn party board on Pinterest and it’ll be here for when you’re ready.

side view of easy cupcakes with a fondant rainbow on top with text which reads easy rainbow cupcakes recipe

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Tips to Make Cupcakes with a rainbow on Top

  • Start with your favorite vanilla cupcake recipe. If you’re anything like me, you definitely need a “no-fail” cupcake in your life, so I always fall back on my Lazy Girl cupcakes. Done right every time–as long as you can follow a basic recipe.
  • If you leave out your fondant rainbows for a couple of hours or, even better, overnight, they’ll stand up really nicely on the top of your cupcakes. But if you’re ok with the rainbows kind of flopping over, feel free to pop those puppies on quickly after making them–they are just rainbows, after all. Ha!
  • I just used fondant I grabbed at my local craft store (stop judging me–that’s where I was and it was and we just found ourselves together in the checkout line), but if it helps you here’s the set of rainbow fondant sampler I snagged.
  • If you’d rather make it homemade, I found this super quick and fun recipe to make your own homemade marshmallow fondant that’s so tasty, it’s amazing.
  • If your heart is just set on it, you can make a cream cheese frosting, sure. But the best, most light and fluffy frosting you can pipe with a decorating bag is this awesome homemade buttercream in this recipe, with confectioners sugar and all the sprinkles you could ever dream of.
  • Always always always let your cupcakes cool to room temperature before you frost them because warm frosting is no fun. Particularly when you’re turning them upside down to dip them in sprinkles. You’re just asking for the frosting to just drop off on the counter then. LOL!
easy rainbow cupcakes with cloud frosting
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How to Make Rainbow Fondant Cupcakes

Below is the written and printable tutorial for this fun cupcake decorating idea. Use the comments section below if you have any questions.

Yield: 12 Rainbow Cupcakes

Rainbow Cupcakes

easy rainbow cupcakes with cloud frosting

These easy rainbow cupcakes are so cute and diabolically simple to make, I feel like I just let the kid do it all! LOL!

Prep Time 10 minutes
Cook Time 25 minutes
Additional Time 15 minutes
Total Time 50 minutes



  • 2 sticks butter, softened
  • 4 cups confectioners’ sugar
  • 2-3 tbsp milk


  • Red, orange, yellow, green, blue, purple fondant (about 2-4 oz. of each color)


  1. Before baking your cupcakes, add blue food coloring into the batter and stir until the color is consistent throughout.
  2. Bake your cupcakes per the directions in the recipe and allow them cool completely before decorating. photo collage tutorial of how to make rainbow and cloud cupcakes
  3. Cream together butter, sugar and milk until light and fluffy to make your buttercream frosting. If your buttercream is too thin, add powdered sugar 1 tbsp at a time. If it is too thick, add more milk, ½ tbsp at a time.
  4. Once the buttercream is light and fluffy, scoop it into a decorating bag with Wilton icing tip #12.
  5. Frost each cupcake by pressing small dollops all over the top to make the frosting look like fluffy little clouds.
  6. To make the rainbows, start by taking a small portion of red fondant and roll out a thin snake about 5 inches long and ½ inch thick.
  7. Arch the red fondant snake on a piece of parchment paper.
  8. Repeat with the other colors, placing one beneath the other in this order: red, orange, yellow, green, blue and purple.
  9. Trim the fondant arch as desired.
  10. Cut each of your rainbows in half.
  11. Place one half- fondant rainbow on top of each frosted cupcake and enjoy! photo collage tutorial of step 2 how to make a fondant rainbow for cupcakes


For more fun cupcake decorating ideas, visit Ruffles and Rain Boots!

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 321Total Fat: 17gSaturated Fat: 10gTrans Fat: 1gUnsaturated Fat: 5gCholesterol: 46mgSodium: 143mgCarbohydrates: 44gFiber: 0gSugar: 42gProtein: 1g

All nutrition information is estimated. For accuracy, please calculate your exact brands and ingredients if accuracy is desired.

Did you make this yummy recipe?

Please leave a comment or share a photo and tag me @rufflesandrain

More Rainbow Party Ideas You Might Like

  • Rainbow Popcorn - One of the most perfect accompaniments to cupcakes is popcorn--particularly when you have a fun party in full swing!
  • Rainbow Bath Bombs - If you want to send your guests home with the most epic of party favors, this is it.
  • Rainbow Cereal Necklaces - This is a blast to do during the party that will make all of your guests squeal!
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photo collage of somewhere over the rainbow cupcakes with text which reads rainbow cupcakes recipe

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