These are the easiest rainbow cupcakes ever! You don’t have to dye multiple colors of frosting to make rainbow frosting! You only need plain white frosting and some sanding sugar.

If you want more rainbow ideas, my daughter loved sewing this hanging rainbow cloud, so easy to make and they make a great party favor.

5 easy rainbow cupcakes with red, orange, yellow, green, purple, and blue layers in polka dot cupcake wrappers, on a white plate

Thank you for stopping by today. Please check out more delicious recipes, comment and let me know how your family liked this one!

To me, rainbows have always represented hope. Hope for peace, happiness, good luck, thanks, and perhaps the pot of gold at the end of the rainbow. These cupcakes are a simple way to bring happiness to others with their vibrant colors and sweet goodness.

These cute rainbow cupcakes are decorated to resemble majestic rainbow stripes. They’re perfect for birthday treats or a sweet treat for any event! Don’t miss what I do to them for St. Patrick’s Day.

Rainbow Frosting Cupcakes Supplies

Note: Affiliate links included in this section.

  • Cupcakes
  • Plain white frosting
  • Piping bags
  • Pastry Tip with 1/4 to 1/2 inch opening (Wilton 1A would work great)
  • Sanding sugars
  • A small bowl or jumbo baking cups
  • Green fondant to make Shamrock toppers (optional)
  • Small Shamrock cookie cutters to make Shamrock toppers (optional)

You will need a rainbow of sanding sugar! Just look at these vibrant colors!

sanding sugar


  • You can actually ask your local grocery store to make you plain unfrosted cupcakes. This will remove the need to bake cupcakes.
  • Another time-saving option is to purchase premade buttercream frosting.

How to Make Rainbow Cupcakes

Begin by baking your cupcakes or purchase plain cupcakes from the grocery store or a bakery. If you bake your own cupcakes make sure to cool them completely before decorating.

Pour colored sanding sugar (not coarse) in small bowls or jumbo baking cups. Fill a pastry bag fitted with a large plain round tip (about 1/2 inch opening) with white buttercream frosting.

red, orange, yellow, blue, purple, and green sanding sugars in jumbo baking cups, and a piping bag with tip filled with white frosting

Using a pastry bag frost the top of the cupcake clear to the edge. Hold tip close to the cupcake to use less frosting. Dip top of the frosted cupcake in red sanding sugar.

cupcake dipped in red sanding sugar, with a pastry bag with tip filled with white frosting, and jumbo baking cups filled with colored sanding sugar

Make another layer of frosting right on top of the red layer. This time don’t go clear to the edge. Bring the frosting in at least 1/4 of an inch.

layer of white frosting added on top of red sanding sugar layer of rainbow cupcake, with jumbo baking cups filled with sanding sugar

Dip the cupcake in the orange sanding sugar.  Rock the cupcake so the edges are completely coated.

cupcake being dipped in orange sanding sugar

Repeat process with yellow sanding sugar and so on…….

sanding sugar rainbow frosted cupcake with red, orange, and yellow layers

until you have a beautiful sparkly cupcake with all the rainbow colors.

completed cupcake with red, orange, yellow, green, blue, and purple frosting layers

They make great Saint Patricks Day Cupcakes when you add a fondant shamrock.

three sanding sugar rainbow shamrock decorated cupcakes

Here’s a mom tip for you. Kids love to help bake and decorate sweets. That’s why I look for things they can help with like this rainbow cupcake. They have so much fun dipping them in the sugar and making all the rainbows.

If you like themed parties like cupcake parties, this is a simple cupcake to decorate. That way everyone will be able to participate in the fun. And when finished enjoy their sweet treat!

More St. Patricks Day cupcakes

Rainbow and Pot of Gold Cupcakes

rainbow pot of gold cupcakes

Pot of Gold Cupcakes

four pot of gold cupcakes with glitter shamrocks lying beside them on a white serving platter

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About Cindy Hopper

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  1. We’ve been having a lousy week so my kid and I just made these and had so much fun! I loved that you didn’t need a bunch of different food coloring. This way was much easier! Thanks for the great recipe.

  2. Oh my goodness – these are just so absolutely darling! I was so curious to figure out what the technique was, and I was thrilled to see that it’s actually very easy! Love this idea – thank you!

  3. Oh my goodness, these Rainbow Cupcakes are absolutely adorable!! I am so excited to try these!

  4. Hey these look so beautiful I have a dear friends birthday and my heart is set out to make them now. running to the shops to get started ! yay thank you xoxo

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