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Rainbow M&M’s first birthday cake


Rainbow M&M’s first birthday cake

I LOVE how Kate’s rainbow M&M’s first birthday cake turned out!  I was so disappointed when Leah’s 3rd birthday cake didn’t work out properly.  I’m so stubborn that I wouldn’t accept the defeat, and I had to try it again on a 1 shaped cake!

Rainbow M&M's first birthday cake |

The problem I had with Leah’s cake, was that the M&M’s dissolved in the homemade icing I made and fell off.  So I didn’t want to take any chances this time.   Since I used the same type of icing and cake as I did for the smash cake, I tested how the M&M’s would stick to the icing the day before I made this cake to make sure they would stick:


I used store bought boxed cake (I made the cake from scratch last time) and I used a tub of store bought french vanilla icing.  Obviously bundt pans were not going to work for a number 1 so I used a 9″x13″ baking pan for the cake and cut out the shape myself.

9x13 cake in cake pan

When the cake came out of the oven, it had a rounded top, so I just used a large knife to slice off the top to make it lay flat:

Slice off top layer of cake to make it flat

I flipped it over on the cutting board and scored the surface of the cake with a knife to sketch out the shape of a number 1.  I didn’t bother using a template – a 1 is pretty easy to guess at:

Score the cake to get the shape of the 1

I cut out the pieces of the cake where I made the score lines:

Cut the cake into the shape of a 1

So here is what the carved out number one cake looked like before it was iced:

Birthday cake cut into the shape of a number 1 |

I transferred the cake over to the cardboard cake board that I saved from the 3rd birthday cake and started icing it:

Birthday cake cut into the shape of a number 1 |

Once it was fully iced, I started with a diagonal row of red M&M’s:

Rainbow M&M's first birthday cake |

And kept adding rows in the order of the rainbow colours:

Rainbow M&M's first birthday cake |

I didn’t think it was going to take a long time, but it did get pretty tedious by the end:

Rainbow M&M's first birthday cake |

With the 3rd birthday cake, I had the problem that the icing was too wet and the M&M’s dissolved and slid off.  This time, I had the opposite problem.  By the time I was done putting them on, the icing was getting too hard, and I had to add some fresh icing to the M&M’s to get them to stick:

Rainbow M&M's first birthday cake |

I was hoping that all the M&M colours would match up along the sides:

Rainbow M&M's first birthday cake |

But on some sections it just didn’t match up:

Rainbow M&M's first birthday cake |

It took about 1.5 hours to put all the M&M’s on:

Rainbow M&M's first birthday cake |

If I had more time, it would have been nice to make a double layer cake by stacking two 9″x13″ cakes and cutting out the number one, but I just didn’t have time.

Rainbow M&M's first birthday cake |

I love the rainbow colours, and I’m so happy I got it to work this time!  I definitely recommend giving it a try!  You can check out the rest of her awesome rainbow party here or other first birthday party ideas here.

That is so cute! It would be great for my little guy’s birthday – he loves “M-e-Ms”. 🙂

Wow! It looks amazing! I can’t believe you were patient enough to spend 1.5 hours putting the M&M’s on. Well worth it, it looks fantastic.

Thanks! Yeah, by the end of the 1.5 hours I was getting REALLY bored of putting the M&M’s on!! 🙂

I believe it! I would have lost it and come up with plan B because I’m not that patient for those kinds of things.

It turned out beautiful, pinning!

So adorable! I love it!

This is so cute and colorful! What a fun cake!

This is great! I’m hosting a new linky party at

I would love to have you!

This cake instantly caught my attention! Definitely pinning to my rainbow treats board! Was it hard to get all the straight lines? It looks perfect.

Thanks! It wasn’t hard at all to get the straight lines. As soon as you get one row, they all kind of just follow along. It was definitely a little time consuming though!

HI Debbie,

Thank you so much for sharing this awesome recipe with Full Plate Thursday. Hope you have a very special Mothers Day Weekend and come back soon!
Miz Helen

Beautiful and I’ll bet it is deloicious.

What a bright, fun cake! I’m trying to think of an occasion to make this!

What a fun cake!! Made with love & M&M’s doesn’t get any better than that! 🙂 Michelle

I love how colorful it is, perfect for the rainbow themed party I am thinking about throwing for my 2 year old.

Great idea! Thanks for sharing!

So cute! Did the color from the M&Ms bleed onto the icing? I was thinking of doing this the night before, but i’m worried it would look bad overnight…

As long as you buy icing in a tub you should be okay. I tried making this cake with homemade milk based icing too and it bled like crazy to the point that all of the side M&M’s fell off. You can search my site for my 3rd birthday cake fiasco to see it.

thanks so much!


Can you give me an idea of how many M&Ms you needed for this? I bought two large bags, but I don’t want to run out halfway through!!!

Do the mm fade or get dull if u do the cake the night before?

Thank you! I made this with 2 layers and used the equivalent approximately 9 individual bags of m&ms. The only problem is there are not the same number of colours in each bag (even if you combine the 9 bags together). I ended up sequencing my colours but alternating between yellow and brown (as there were the fewest of these colours). Also, I ran out of reds. I made it with cream cheese icing and it also bleeds but since I had already made the icing the night before and didn’t want to throw it out, I added cocoa powder so that it would show less. Turned out ok but wouldn’t suggest doing it too much in advance.

I never baked this cake but after seeing its positive reviews, I will surely bake this cake in this weekend.
Always i baked such excellent cakes from the site :


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