rainbow marble cake_lc.jpg

Rainbow Marble Cake

Prepare to be mesmerized by this rainbow marble cake!


  • Cake:
  • 430 g 15 oz plain (all-purpose) flour
  • 265 g (91/2 oz) caster (superfine) sugar
  • 3 teaspoons baking powder
  • 1/2 teaspoon fine salt
  • 125 g (41/2 oz/1/2 cup) unsalted butter, softened
  • 2 large eggs
  • 375 ml (12½ fl oz/11/2 cups) full-cream (whole) milk
  • 125 ml (4 fl oz/1/2 cup) vegetable oil
  • 2 tablespoons Greek yoghurt (or sour cream)
  • 1 teaspoon vanilla extract or vanilla bean paste
  • 4 drops teal food gel
  • 2 drops pink food gel
  • 4 drops yellow food gel
  • Decorations:
  • 650g white fondant
  • 1 tbsp pink liquid food dye
  • 1 tbsp blue liquid food dye
  • 1 tbsp yellow liquid food dye
  • 1 tsp gold lustre dust + 1 tbsp rose spriti
  • Frosting:
  • 500g softened unsalted butter (softened)
  • 500g powdered sugar
  • 2 tbsp milk (room temperature)
  • 1 tsp vanilla extract


  1. Frosting
  2. Use a stand mixer or hand mixer to soften butter in a large bowl and mix for 5 minutes so it gains some volume and goes pale in colour.
  3. Add the powdered sugar and vanilla extract into the bowl and mix on low speed to begin with. Once the sugar has mixed in enough with the butter, bring to high speed and whip for another 6-8 minutes until the buttercream becomes fluffy. If you want to make your buttercream a little less stiff and smoother add milk and whip in until well combined.
  4. Cake
  5. Please note: to make the 4 layered cake in this recipe, you’ll need to make 2 batches of vanilla cake. All other recipes and measurements are enough to put the cake together and decorate it.
  6. Preheat a fan-forced oven to 140C (280F) or 160C (320F) for a conventional oven. Spray two 7” cake tins with oil spray and line the bottom with baking paper. Set aside
  7. Add the flour, sugar, baking powder and salt to a large mixing bowl and mix together using a hand mixer until well combined.
  8. Next add the softened butter and mix on low speed until mixture reaches a crumbly sand like texture.
  9. Add the eggs, milk, oil, Greek yogurt and vanilla extract. Mix on low speed until no dry ingredients are showing. Scrape down the bowl and mix for another 20 seconds.
  10. Split the batter into three different bowls and colour one teal, another pink and the third yellow using food gel colouring. Mix until well combined.
  11. Spoon the different coloured batters into each cake pan alternating between each colour.
  12. Bake for 50-60 min or until a toothpick inserted comes out clean. If the pick comes out with wet batter, bake for a further 10 min at a time until fully baked. Allow the cakes to cool to room temperature inside the cake tins and then chill them in the fridge overnight. Chilling your cakes overnight makes them easier to trim and decorate. So I bake my cakes the day before I decorate them.
  13. To trim your chilled cakes, use a cake leveller or large serrated knife to carefully trim the crust off the top of each cake before you trim each cake in half. You’ll end up with 6 layers of cake.
  14. To crumb coat your cake, add a dab of frosting onto an 8” cake board or flat serving plate. Use a small offset spatula to spread the frosting around before adding the first cake layer. Gently press down the centre of the cake layer to make sure it’s stuck to the frosting underneath.
  15. Add frosting to a piping bag and frost a ring around the top of the cake. Fill the centre with more frosting. Use your small offset spatula to smoothen out the frosting before you add the next layer of cake. Repeat with the remaining layers.
  16. Add more frosting around and top and sides of the cake. Use the small spatula to smoothen out the top and sides of the cake, taking care to fill in any gaps in between each layer of cake.
  17. Use a cake scraper (otherwise known as a bench scraper) to smoothen out the frosting on the sides and top. Get it as neat as you can. This should just be a neat, thin layer of frosting which is aimed at trapping any cake crumbs so that random bits of cake crumbs don’t show up on the final layer of frosting. Chill for 2 hours or overnight.
  18. Your cake is now crumb coated and ready to be covered in fondant! To prepare the fondant, you’ll need a large fondant roller. Dust a smooth work surface with powdered sugar. Place your ball of fondant on top and use the fondant roller to roll out your fondant to about the size of two large plates and about 1cm in thickness.
  19. Carefully roll the fondant over your rolling pin and lift up and place on the cake. Use the palm of your hand to stick the fondant to the top of your cake before working the sides with the palm of your hand. Cut off any excess fondant with a small sharp knife before working on the very bottom of the cake. If you find your fondant looks lumpy once it’s on the cake, keep working it with the palm of your hand to smoothen it out.
  20. For the next part you’ll need three sea sponges. You can grab these from your local craft store in the paint section. Just make sure you give them a good wash before you use them and let them dry for a couple hours. Dip each sea sponge into your food dye and dab it onto the cake. Leave some parts white.
  21. To prepare the gold paint add gold lustre dust into a small mixing bowl along with rose spirit and mix until well combined. Use a small food safe brush to brush lines that look like little rivers on the fondant. This will give the cake a marble cake.