How to make a rainbow cake tutorial

Are you planning a rainbow party and looking for a Rainbow themed cake? This week I’m creating a sweet polka dot rainbow topper surrounded by 3D clouds. This is such a cute design and the colours can all be changed to match your theme.

In the tutorial I also go through how to use the SweetStamp letter sets to personalise your cake with text on the front.

Watch the tutorial below ⇩

The cake in the tutorial is a 6 inch cake, 5 inches in height, but the rainbow can be made any size to fit any cake. For the rainbow I used gumpaste (Squires floral paste) so it would try quickly and keep its shape. The rainbow was ready to add onto the cake after around 2 hours of drying time.

If you don’t have any gumpaste you can add some Tylos powder into your fondant, as this will help it dry a little firmer.

Fondant Clouds

If you’re creating a cake which is based around a sky theme, 3D fondant clouds are are great addition. These are made by placing different sized balls of fondant together and placing a thin rolled out piece of fondant over the top, giving the appearance on one large fluffy cloud. I kept my clouds white, but you could add some edible dust colours to add some shadow.

How to make a rainbow cake topper

SweetStamp Letter Sets

If you’re creating this cake as a birthday cake, it’s always fun to personalise the cake, either with text as I have or you could also add a name or age onto the front, or on a fondant covered board.

In the tutorial I also use the Cutie Pie SweetStamp letter set to add the ‘Party Time’ onto the front. This is such a fun letter set and is perfect for children’s birthday cakes.

Sweet Stamp have kindly given me a 10% off voucher code, to give to all of you, if you purchase from their website. That includes all the letter sets,  the brushes, paints, stencils and so much more!

To receive the 10% off all you need to do is visit their website and enter the code ‘CAKESBYLYNZ’ at the checkout!

Sweetstamp Cutie pie set

Tools I used

I have put a list below showing all the tools that I used throughout this video or if you would like to see all my favourite cake decorating tools just click here:

SweetStamp Cutie Pie set:  (Use code CakesbyLynz for 10% off)
SweetSticks Lustre – Glamousous Gold: (Use code CakesbyLynz for 10% off)
SweetStamp Brushes: (Use code CakesbyLynz for 10% off)
SweetStamp Texture Tools: (Use code CakesbyLynz for 10% off)
SweetStamp Pickup Pad: (Use code CakesbyLynz for 10% off)
White Edibleart Paint: (Use code CakesbyLynz for 10% off)
Happy Sprinkles Pastel Vibes: (Use code HappyLynz10 for 10% off)
Extruder Gun:
Round Cookie Cutters:
Modelling tools:
Edible glue:
Renshaw Fondant (White):
Squires Petal Paste (Gumpaste):
Dipping Solution:
Rolling Pin:
Glass Cutting Board (similar):
Renshaw White fondant:
Plastic Smoothers:
Squires Kitchen Belissimo Flexi Smoothers:
Raspberry Colour Splash:
Jade Colour Splash:
Yellow Colour Splash:
Violet Colour Splash:
Black Colour Splash:

~ Please note that some of links above may be affiliate links. If you click the link and purchase any item through that link, I will receive a small commission from the website but this does NOT add any additional costs to you. Thank you so much for supporting this blog x ~

Plus why not save this tutorial for later and pin it to Pinterest


How to make a Rainbow Cake Tutorial