Pre-heat oven to 180°C/160°C Fan/Gas Mark 4. Grease and line 2 x 6” deep round cake tins. Cream together the margarine and sugar until pale and smooth.

Mix in the eggs and Vanilla Extract – if the mixture begins to curdle add a spoonful of flour. Sieve the flour, Baking Powder and Cocoa Powder on top and fold into the mixture until all combined.

Divide the mixture between the cake tins and bake for 40-45 minutes until the cakes have risen and a skewer inserted into the centre of the cake comes out clean. Leave to cool in the tins for 15 minutes and then remove and leave to cool completely on a wire rack.

Place the butter in a freestanding mixer a beat until smooth and glossy. Gradually add the icing sugar making sure it is mixed into the butter after each addition. Once all the icing sugar is add the Vanilla Extract and turn mixer upto a high speed. Beat the buttercream until light and whipped in texture. 

Divide the buttercream equally between 6 bowls. Add a different colour to each bowl and mix until the colour is evenly mixed through the buttercream. Place each colour buttercream into a separate piping bag.

Lay a piece of cling film onto your work surface and pipe a strip of each colour buttercream onto the cling film, starting with pink then orange, yellow, green, blue and purple. – make sure the lines of buttercream are not too thick and they should be touching each other. 

Once you have piped a line of each colour buttercream roll the cling film to create a sausage shape. Cut the end of the cling flim to reveal the buttercream at one end. Place the cling film into a piping bag fitted with a star nozzle. 

Level the top of each sponge and cut in half to create 4 layers of sponge. 

Place the first layer of sponge onto your serving plate or cake board. Pipe buttercream swirls onto the sponge layer and place the next sponge layer on top. Repeat until all the sponges are sandwiched together. If you run out of buttercream refill as above.

Break up the Chocolate and place in a microwavable bowl. Melt the chocolate in the microwave in 30 second bursts, stirring after each burst until melted. 

Pour the melted chocolate onto the top of the cake and spread to cover the cake using a palette knife. Pipe buttercream kisses onto the top of the cake in a crescent moon shape – if you have different nozzle use a variation of nozzles to create different shaped buttercream kisses. 

Sprinkle with Unicorn Confetti Sprinkles to finish.