Lightly crush the digestive biscuits and chop the marshmallows in half or quarters. Chop the various Easter eggs into small pieces.
In a large bowl place the broken digestive biscuits, chopped marshmallows and Easter eggs and mix.
Melt the butter, golden syrup, milk chocolate and dark chocolate together and pour through the the rest of the ingredients. Mix quickly and press into the prepared tin in an even layer.
Place in the fridge for one or two hours until set. Cut with a sharp knife into pieces and serve.