Will banana cake and banana cream filling be too much banana flavor?
Since this is for young kids, I’d say it’s better to play it safe and just go with the cream cheese frosting for both filling and exterior. The banana refrigerator cake has a nice banana flavor but is not overly strong, they will probably love it if they like bananas.
I know that the Tropical Wedding Cake (page 391) pairs the banana cake with a passion mouselline filling but I don’t think passion fruit is a flavor kids would enjoy.
Also, can I use the batter for the two 12 X 2 inch pans (Tropical Wedding Cake, page 392) and bake this in two 13 X 9 X 2 quarter sheet pans?
I don’t have my book in front of me, so I’ll have to do this geometrically. The volume of a 9x13x2 pan is 234 cubic inches, while the volume of a 12x2 circle pan is 226 cubic inches. You could probably do it if the cake for the 12” pan is filled 2/3 full (does the recipe say?). As for leavening, you should be OK.