Rainbow Cake

My friend asked me if I could help with the cake for her daughter’s birthday because she wanted a rainbow cake. I looked online a little because I have never used fondant so I didn’t know where to start and how to make a little rainbow to put on the cake! Turns out there is a lot of tutorials online on how to make rainbow cake and rainbow fondant decor! So here is mine!

The fondant rainbow decor:

First thing you have to do is plan in advance! You will need to make your rainbow cake topper 3 to 5 days ahead to allow it to dry and stand up on the cake.

I used white fondant and gel food colouring. Gel is better because it won’t change the texture of your fondant!

I made little balls of fondant for each colour, I did 7 because I wanted a real rainbow but you could do 6 or even 5 if you prefer! Your red ball will be the biggest one because it goes on the outside of the rainbow and the purple ball will be the smallest because it goes on the inside of the rainbow. Then, roll your balls to make little snakes and place then in the shape of a rainbow. Use water to stick each snake to the other. I made a little snail shape at the end to make it prettier because it is for a little girl but you don’t have to!

I used the left over coloured fondant to make little hearts with a cookie cutter. Between 3 and 5 for each colour. Then, I used the white fondant to make clouds with a knife. While I was doing the clouds, my daughter mixed all the left over balls to make a bigger ball so I ended up with a a ball of grey fondant. So I decided to add some grey clouds! I also used yellow fondant to make a little sun because in order to have a rainbow you need the sun and some clouds!

I let all that fondant dry up for a few days on parchment paper, turning them upside down every day.

The rainbow cake:

Here you have a choice! You can do any cake you want but being a perfectionist, I wanted the inside to be a rainbow as well!

So I decided to go with sponge cake and whipped cream because it is made for kids so I wanted it simple.

Sponge cake is very fragile. So instead of making a big batch of batter and separate in 7, I chose to make 7 different batch of batter. That way the batter would stay light and airy!

So I used one egg, 30g of sugar and 30g of flour for each colour! It is time consuming but the result is so much better. Your batter will be perfect and each layers will be the same size.

Once I have baked my 7 cakes and let them cool down, I started to make my rainbow cake. I made a simple sirup with sugar, water and vanilla. Then brushed the sirup on each cake and stack them with whipped cream in between.

I covered the cake with a thing layer of whipped cream and let it set in the fridge for a few hours.

Then I used blue whipped cream to cover the 3 third of the cake and let the top in white to represent the sky and the clouds.

At the last minute, at place all my fondant rainbow, clouds and hearts and voila! The perfect rainbow cake!

If you are looking for a different kind of birthday cake check out my Dinosaur Cake tutorial here!