I just tried the white on white buttermilk cake recipe for the first time a couple of weeks ago, this one: http://www.bakespace.com/recipes/detail/White-on-White-Buttermilk-Cake-with-Jack-Daniels-Buttercream/7175/

I LOVED the flavor, but I noticed it was a little more crumbly than I might need for stacking a four-tier cake. Has anyone used it for stacked cakes? Did it hold up? Thanks!!

That cake is crumbly because it is over leavened. There is enough leavening for 4.5 cups of flour and it only has three. Try adjusting the leavening and you will get a less crumbly cake. More leavening = more crumbling.

BTW you can stack any cake with the right stacking stuff. The SPS system talked about here on CC would work well.

Ahhh...just noticed there was a reply to my post!! Thanks for the tip LindaF144a!! I tried using AP flour the second time around, thinking the gluten would help hold it together better, but it tasted to me like sweet cornbread. Do you think reducing the salt, baking powder, and baking soda by about one-third would do the trick?

I don't think you need to reduce it by a third. The salt won't affect the leavening. But if you want to take some of that out, it is a personal preference. The cake might be a better if the baking soda was reduced to 1/2 tsp and the baking powder reduced to 1 tsp. Personally I don't bother to neutralize the buttermilk in a recipe as the acidity does help. But with the cake flour and the buttermilk it might be too much acidity, so a little baking soda will help. 1/2 tsp will neutralize 1 cup of buttermilk, so that will leave 1/2 cup unneutralized and that will help.

I have not tried this myself, but possible beaten egg whites would help with the structure too. But you want to change one variable at a time in a recipe, so start with the leavening. I have over leavened cakes and under leavened just to see the results. When there is too much leavening, the cake is so light and not held together that it crumbles when you cut into it. So that is why I suspect the amount of leavening is off.

The white recipe I use is moist and has a tender crumb. When I first baked it it was pretty soft and crumbly so I was nervous about the structure, but I was able to ice three tiers in white buttercream and stack them and transport the cake 20 miles without any problems . I think as long as you've crumb coated and then fully frosted each tier to lock all the crumbs/cake in, and as long as you have plenty of inner-support, it'll hold up fine. I use the big plastic bubble tea straws too (8 per tier) for inner support.

Thanks so much guys!! LindaF144a, that's such very useful information! In fact, I have one more opportunity to make the recipe with the modifications you suggest before I need it for the BIG day. Thank you!!