I'm having problems everytime I make a soda cake.  I normally just buy the Duncan Hines (vegan) cake mix and then use the right amount of soda (8 to 10 oz).  This is all the recipe calls for and people say it's a great recipe, but I always get a real sticky and crumbly cake.  I can't even get the cake out of the pan without it falling apart on me.  Icing is pointless to have because the cake breaks away if I try to put some on it.

So my question is......what the heck am I doing wrong?  ???