Rainbow Birthday Mud Cake

Place buttercream into a stand mixer fitted with a beater attachment and beat until soft and fluffy.

Arrange 1 of the mud cakes, icing side down, on a cake board or serving plate. Pipe some buttercream around the edge and fill with a mixture of Dollar Sweets Colours of The Rainbow Sprinkles. Repeat with second and third mud cake, making sure the icing is facing down.

Pipe buttercream over the top and sides of the cake. Use a spatula or cake scraper to smooth. Refrigerate for 2 hours.

Spoon 3-4 tbsp of buttercream into 5 small bowls. Colour each bowl with a different Dollar Sweets Food Colour of your choice. These colours will be used to paint the cake. Colour the remaining buttercream with another colour. This colour will be used to pipe the rosettes on top of the cake.

Fit a piping bag with a 6B open star tip and pipe rosettes onto the top of the cake. Sprinkle with a mixture of Dollar Sweets Colours of The Rainbow Sprinkles and Dollar Sweets Party Sprinkles, then arrange Dollar Sweets Colourful Candles to decorate.

Using a small paintbrush, pick up a pea-sized amount of coloured icing on the end of the brush and gently press onto the side of the cake to adhere. Then apply light pressure to make a brushstroke. Repeat all over the cake in random areas. Repeat with remaining colours, remembering to thoroughly wash the brush between colours.

Press extra sprinkles in sections on the sides of the cake, if desired.