The Art of Cake: A (Mostly) Silent Post


5.0 from 1 reviews
1970s Rainbow Cake
A retro birthday cake to remember. Reminiscent of simpler times, yet mightily impressive and completely enchanting.
  • For the cake:
  • 300 g (12 oz) self-raising flour (I used ½ whole wheat, ½ white)
  • 300 g (12 oz) Demerara sugar (or white caster sugar if you prefer)
  • 300 g (12 oz) butter, softened
  • 6 eggs
  • red, blue and yellow food colouring
  • For the frosting:
  • 300 g (12 oz) butter, softened
  • 650 g (24 oz or 1.5 lbs) icing sugar
  • food colouring of your choice
  1. Cake:
  2. Preheat oven to 180 C / 350 F / Gas 4.
  3. Grease and line 6 small (I used 7-inch / 18 cm) cake tins and set aside.
  4. Sift the flour into a large mixing bowl then add the sugar and butter and mix.
  5. Beat the eggs in a small bowl then add to the cake mix and beat well.
  6. Weigh the mix (make sure to deduct the weight of the bowl - my scales do this automatically if I put the empty bowl on the scales before turning the scales on).
  7. Divide the mix evenly (by weight) between 6 small bowls.
  8. Colour the mix in each bowl a different colour to make up your rainbow. Remember your colour mixing skills from kindergarten!
  9. Spoon each batch of coloured mix into a separate cake tin and bake two at a time for about 20 minutes or until the top is springy and just starting to brown.
  10. Remove to a cooling rack, cool in tin for 10 minutes then gently remove and cool completely.
  11. Frosting:
  12. In a large bowl beat the icing sugar with the softened butter until creamy. You can either colour the entire batch or (as I did) use some plain as 'glue' between the cake layers, then colour the rest for the outside.
  13. Decide what order you want your coloured layers to be and start stacking. I put a blob of frosting on the base of the cake plate to hold the cake in place, then started with the brown layer.
  14. Gently spread about 2 Tbsp of frosting over the first layer, then put the next cake on, making sure to keep it centered.
  15. Continue, using all your layers and about ½ your frosting. If the cakes are lopsided at all, try positioning them so that the bump of one makes up for the hollow of another (if that makes sense) to prevent the whole thing from falling over. I put the top cake upside-down so I'd have a flat surface to frost and decorate.
  16. Colour your remaining frosting if you like (most rainbow cakes out there are frosted in white but my son chose sky blue and I thought it quite fitting), then cover the cake in it. I did a 'rough' layer, to make sure it was covered, then went back with another layer to smooth. The final touch is to go over the frosting with a knife dipped in hot water, as this slightly melts and smooths the frosting. I wanted a homemade rather than professional look, so I only smoothed it a bit.
  17. Decorate according to your occasion, and be sure to have the cameras ready when you cut it!
1. I can't give you exact measures for how much food colouring to put in each batch as it will depend on the type of colouring you use and how yellow your mix is. My mix, due to the whole wheat flour, free-range eggs and brown sugar, was quite yellow/brownish, which ultimately gave the cake that trademark 1970s cast. If you want truer bright colours, use white flour and sugar. 2. I'm not too paranoid about using artificial colourings, especially if it's only once or twice a year, but if you would like to try using natural food dyes, check out this tutorial. 3. Remember that this is a very tall cake, with lots of frosting in between layers, so cut the pieces thin. A little goes a long way!