Helen - I am from the US and have never heard of "American White Cake" either, but what I commonly hear is that British use fruit cake for their wedding cakes. And while I have no doubt that yours are awesome, ours are not very popular and are the brunt of many jokes (like how the fruit cake given to Aunt Sally for Christmans just keeps circulating year after year because nobody will eat it). My family loves fruit cake but many do not, so maybe that's why your bride is asking. Maybe you could let her taste what you normally would use; she might love it because chances are it's not the US fruit cake that she's invisioning. But any white cake recipe you'll find here on Cake Central should work just fine. Just make sure to read the comments to make sure you find one that is described as both moist and firm; most comments will tell you if the cake is suitable for carving, stacking, etc. And if you can't find particular ingredients listed, holler back at your CC community and let us help you figure out substitutes, etc. I would say that the most popular white cake here on CC is the WASC - White Almond Sour Cream. It's moist, firm enough to carve or stack, and a huge favorite. You'll find many recipes for it both from scratch and from using a cake mix as a starter. Good luck and have fun!!