Join Cupcake Jemma as she creates a scenic Rainbow Meadow Buttercream Cake using all the colours of the Colour Mill x Cupcake Jemma collab pack.


  • 500g Caster Sugar
  • 135g Vegetable Oil
  • 330g Butter, room temperature
  • 8 Large Eggs
  • 500g Self Raising Flour, sifted
  • 6 tbsp Milk
  • 1 tsp Vanilla
  • Colour Mill x Cupcake Jemma
Oil Blend Colouring

Cupcake Jemma x Colour Mill Pack

calculated at checkout
Cupcake Jemma's very own top 12, must-have pigments for bolder and brighter baking.


Sponge Cake

  1. In your mixer beat together your butter, sugar & oil using the paddle attachment until your mixture is pale and fluffy.
  2. Add your egg 2 at a time, beating for 30 seconds after each pair.
  3. Next add your flour by folding it in slowly until just combined.
  4. In a seperate bowl, mix together the vanilla and milk.
  5. Lay out 6 mixing bowls and place 1tbsp of milk in each bowl. Add one colour to each bowl of milk, using 2-3 drops per colour and stir into the milk.
  6. Weigh your batter and evenly it divide between the 6 bowls.
  7. Fold the coloured milk through your batter. You want to do this gently so you don't knock the air out of the batter!
  8. Now your batter is ready, place each colour in one 8" greased pan, levelling the top of them with a spatula.
  9. Bake in the oven at 170C for 20 minutes or until toothpick comes out clean.
Let's Bake a Rainbow Cake using the Cupcake Jemma x Colour Mill Collab pack!


  1. Allow cakes to cool, then level and trim each layer.
  2. Dab a small amount of white buttercream onto the centre of your cake board, placing your Purple cake layer on top.
  3. Place a generous amount of white buttercream over the top of this layer and smooth it out to create a flat, even surface. Stack your Sky Blue layer on top & repeat this process until all layers are stacked.

Crumb Coat

  1. Once all layers have been stacked, it's time to crumb coat. Start by piping zig-zagged lines of white buttercream all over the sides and top of your cake.
  2. Using a palette knife, spread the buttercream out across the sides of your cake.
  3. Using a cake scraper, even buttercream out, creating a flat layer of icing across the sides and top of your cake.
  4. Once completed, place your cake in the fridge for 30 minutes to firm up.


  1. Now your cake is firm, we can start decorating the buttercream scene. You will want to start with the background, working your way forward to the foreground.
  2. Starting with the background, add 2-3 drops of Sky Blue into your buttercream, adding more as desired. Tip: Try making the buttercream the night before to get full colour depth.
  3. With a similar technique to the crumb coat, spread your buttercream around the outside of the cake, smoothing it with your cake scraper.
  4. Place in the fridge for 10mins to allow buttercream to firm up.
  5. Divide buttercream into 7 bowls, and add one colour to each bowl - Hot Pink, Lavender, Sky Blue, Lime, Yellow & Orange.
  6. Place each colour into a piping bag with a No.2 Round Tip attached.
  7. Remove your cake from the fridge. Mark the outline of your hills and rainbow using a toothpick.
  8. Outline the hills with your Lime buttercream and then roughly filling in the centre. Use a palette knife to smooth the hills out.
  9. Now pipe your clouds using white buttercream. Blob the basic shape of the clouds then smooth out with your palette knife.
  10. To make the rainbow, pipe your first line as straight as possible then the second line approx 1cm apart. Roughly fill the space between with buttercream and use your palette knife to smooth it out.
  11. For the next colour, you will only need to pipe the outside line and roughly fill the space in between. Spread your buttercream with a palette knife, smoothing it slightly into the first colour. Repeat this step for all colours.
  12. Pipe the final cloud for the end of your rainbow, as outlined in step 9.
  13. Now your rainbow is complete, you can pipe your flowers on the hills. It is up to you how you would like these too look!
Let's decorate our Rainbow Cake using the Cupcake Jemma x Colour Mill collab pack!
Oil Blend Colouring

Cupcake Jemma x Colour Mill Pack

calculated at checkout
Cupcake Jemma's very own top 12, must-have pigments for bolder and brighter baking.
Written By Colour Mill x Cupcake Jemma