Lori, I mainly want to say hi. It was great to see your name again among the postings! You must be very busy. Will add my congrats to Jeanne’s and hope to get my hands on a copy of the magazine to see your picture.
Had a look in my books re: your query. No champagne cakes as such. But one suggestion: what about a champagne sabayon filling stabilized with gelatin? Since the filling would be so rich, you could pair it with a leaner cake. Vanilla? Also checked online. Lots of rubbish about cake mixes and pink champagne. I did find one scratch champagne chiffon cake on a blog. The same one, I believe, that was posted to Rose’s blog, which she advised would only work in a tube pan. Here’s the link: http://bakingbites.com/2007/12/champagne-chiffon-cake/
My CIA baking and pastry book says that batters made by the chiffon mixing method are more stable than batters in which beaten (foamed) eggs are used. According to them, the method produces a tender, moist crumb with ample structure and stability, making it a good choice building tiered cakes. Their chiffon cake recipe offers several variations but not one with champagne. Perhaps you could come up with your own variation?
Good luck with it! Would love to know how you make out.