I liken this recipe to a pear and apple crostata with a sweet caramel drizzle. The pear , brown sugar ,double apple , and Fuji pair perfectly to create that fruit filling. Graham cracker , yellow cake , and cereal 27 create the perfect crust with the cereal 27 there for the "crunch". Marzipan is there to add that extra depth and twist in this complex recipe. The caramel pulls double duty IMO it helps bolster the apple filling adding sweetness as well as being the caramel topping. The Bavarian cream adds a nice buttery feeling to the recipe and ties it all together. Add I n optional sweetner if so desired for that sugar lips effect.