Gluten free dairy free twinkie cake shortcake

So, my 13 year old has never had a Twinkie. She had her Celiac diagnosis at such a young age that she never had a chance to know about this miracle food. I thought to introduce her to this cultural phenomenum by making a homemade cake version, but my end product must be called a strawberry shortcake because it really tastes nothing like Twinkie. Still, it's gluten free, dairy free and fun. If I ever do this again, I will follow Elana's recipe, here.

What I did to create the image above was to mix up a Bob Red Mill vanilla gluten free cake mix. This is not my favorite vanilla gluten free cake. In fact, I am not sure why I bought it for this purpose, except that the sale jumped out and spoke to me. This mix has a nice flavor, but the texture is more of a muffin and less of a cake, with a defined granular texture that is not what I was looking for. My favorite white or yellow gluten free cakes are more the style of my Lemon Angel Food, here. For some, however, these types of recipes are a bit tricky as you have to fold the egg whites in carefully and not over mix. When done well, the result is delightful.

To accomplish this filling, I did a traditional egg white whip with cream of tartar followed by a simple syrup made of honey and water. Elana's recipe uses agave nectar, and I have to say that it would have been better. While I love honey very much, the flavor of the honey overwhelmed the rest of the whipped filling, and that just didn't create the flavor effect I wanted. So, for honey cake, it would have been great, but for this, I think sugar or agave would have worked better.
Still, with enough fresh fruit, I think we can manage to eat it. ;)
What's your favorite gluten free vanilla cake?