cakes-layers-ice.rb

class Cake < ActiveRecord::Base
  has_many :layers
end

class Layers < ActiveRecord::Base
  belongs_to :cake
  belongs_to :creation_setting, :polymorphic => true
end

class IceCreamLayerSetting < ActiveRecord::Base
  has_one :layer, :as => :creation_setting
end

class PhylloLayerSetting < ActiveRecord::Base
  has_one :layer, :as => :creation_setting
end