All you will need is a cake which you can either bake or purchase (depending on your skill set), cake icing, Kit Kats in which ever flavour you like, and a bag of colourful M&M's.
Firstly the cake needs to be relatively flat on top so that the Kit Kats are higher that the cakes edge and the M&M's sit in the centre. You may wish to cut the top of the cake for a flatter surface.
Then you will need to ice the cake all over, especially on the sides.
You can then stick pieces of Kit Kat around the edge of the cake in a vertical position. Make sure they stick to the icing and are higher than the top edge of the cake. These can be all the same colour or a mixture of white chocolate, milk, or dark chocolate Kit Kats.
Now all that is left to do is to fill the top of the cake with M&M's making sure they are no higher than the Kit Kat barrier.
The cake can also be finished off with a ribbon around the Kit Kat edge.
Now you can enjoy a fun, colourful party cake that was simple to make and will be delicious to eat.