Complex sentence: The Cherries Jubilee needs to be more jubilant, so brandy is added to them-unfortuantely both Niles and Frasier do this, several times each, without the other knowing.
Split into simpler sentences: The Cherries Jubilee needs to be more jubilant, so brandy is added to them. Unfortunately both Niles and Frasier do this, several times each, without the other knowing.