I can't believe that after almost 2 years of professionally baking I have had this problem few times with different recipes!! Even the WASC, which is the easiest cake in the world!!
Ok so I follow the recipe exactly the same way that I have done the past two years, and all of a sudden I bring the cake out of the oven, and feel the weight and unusual heaviness...
And when I cut the cake, I realize that the bottom half is too dense, has a gummy texture and has bubbles(air tunnels) in it. The cake doesn't ask for cake flour, and nothing is expired... The same recipe that always works, suddenly doesn't work!!
What could be the problem?? I have troubleshooted everything and I am completely out of ideas now!! Would appriecate any input!
I have the problem if my cake isn't quite done when I take it out. You said you've made this cake for years so I'm not trying to be insulting, but maybe your oven isn't getting as hot at as it used to? Before I replaced my last oven, it started to break down pretty quickly and not cook the same as before. When the guy came to work on it, it was temping way lower than what the oven said it was it.
I've also found that if I take my cake out when it's just barely done, even when the toothpick comes out clean, sometimes it still needs a few more minutes to avoid that gummy texture you're having.
So many different things can come into play; pan size, different pans, mixing methods, etc. Again, I don't mean to come off as insulting because you sound like you know what you're doing! HTH!
It's a leavening issue. It could be as simple as using the wrong ingredient (grabbing the baking soda instead of baking powder) to having too much liquid to dry ingredients weighing the cake down. Using cake flour when before you were using ap flour.
Its either; a mistake your making if the recipe once worked and now it doesn't or if the recipe never worked it's out of balance.