I think its the fuji. If you have banana and fuji just play with those two.
There is more to banana plus apple than meets the eye. Banana fans, butterscotch fans, and meringue-fruit-pie fans, some info for you - it all ties together at the end, I promise.
In making a butterscotch pudding (vape) recipe, FA Butterscotch was just not right with my other ingredients, so I set off researching real butterscotch.
Original (Doncaster) butterscotch used cream of tartar. That's the stuff scraped off wine barrels after winemaking. It's an acidic salt. In the candy, it was used to prevent crystalization, but it has a flavor of its own, likened to apples. In fact, cream of tartar can make a chemical apple pie that tastes like sweet apples but contains no apples at all. I gotta make that sometime.
So I began playing with a little FA Apple and Apple Pie flavorings in my butterscotch, and added it all to my rummy stuff. Along the line I got a great butterrum pudding. One trial tasted like the perfect start of Banoffee (banana toffee creamy pie thing), so I added 2% FA Banana. I expected I'd need lots more, but was surprised I don't. Making the same combination without the Apple or Apple Pie flavorings, it tastes like a toffee-butterscotch pudding, but the banana is only barely there.
So yes, apple flavors do something to banana...and to butterscotch-toffee flavors. I'm going to play with various combinations of Apple, Fuji, Apple Pie to get my (rummy? pudding? pie? haven't decided) Banoffee just right. There's no doubt that some kind of apple is needed for both an authentic Doncaster butterscotch-toffee and for the banana in my recipe.
Banana + cream of tartar (FA Banana plus some combination of FA apple flavors) makes sense. Some banana bread and banana cake recipes use cream of tartar. Real meringue (think banana cream pie) uses it. It's not for the same purpose we'd use it for in vaping, but if it's there in the foods we eat, we'll associate those flavors. I made a note to figure out if FA Meringue includes a note of apple for the cream of tartar, but I won't play with that any time soon. But if the fruit in your fruity-meringue pie needs a boost or doesn't taste quite right, apple is a likely addition -- very tiny bit, probably Fuji for brighter fruits.
The way we've used FA Apple Pie to get the crust flavor for pies without the apple flavor... - same idea is at work, but the apple is standing in for cream of tartar. Maybe that's in part why FA Apple Pie for pie crust works so much better than using TFA Pie Crust or FA Cookie without the Apple Pie.
Sorry I'm in a rambling fugue state...lol! I just know this will all prove valuable info for pies, banana stuff, butterscotch, and probably other fruity (vape) recipes.