No-bake watermelon buttercream cake

This no-bake watermelon buttercream cake is the perfect dessert for when you're strapped for time but still need to wow a crowd.



Note: + 30 mins setting time



  • 3 Coles White Mud Cakes or Chocolate Mud Cakes
  • Pink liquid food colouring
  • Green liquid food colouring
  • Cornflour, to dust
  • 50g ready-to-roll black icing


  • 500g butter, softened
  • 1kg icing sugar mixture
  • 1/4 cup (60ml) milk



To make the buttercream, use an electric mixer to beat the butter in a large bowl until very pale. Gradually add the icing sugar, beating well after each addition. Add the milk and beat to combine. Reserve a little of the buttercream in a small bowl. 


Use a large serrated knife to trim the top of each cake to level. Place 1 cake on a serving platter and spread top and side with a little reserved buttercream. Top with another cake and spread the top and side with a little more reserved buttercream. Repeat with remaining cake and reserved buttercream. Place in the fridge for 30 mins to set.


Divide remaining buttercream into 6 portions. Tint 1 portion dark green, 1 portion pale green and 1 portion pale pink. Leave 1 portion white. Combine remaining 2 portions and tint dark pink.


Place each portion of buttercream in separate piping bags fitted with 5mm plain nozzles. Pipe the dark green buttercream around the base of the cake. Pipe pale green buttercream above the dark green layer. Pipe with white and pale pink buttercream, stopping halfway up the side of the cake. Pipe dark pink buttercream over the remaining side and top of the cake. Use a palette knife to smooth the sides and top of the cake.


Dust a clean work surface with cornflour. Use a small rolling pin to roll out the black icing to a 1mm-thick disc. Use a small round cutter, or the tip of a piping nozzle, to cut discs from the icing. Pinch to make teardrop shapes.


Decorate the cake with the black icing ‘seeds’. 

Check ingredient labels to make sure they meet your specific dietary requirements and always consult a health professional before changing your diet. View dietary information here.