There was waaaaay too much liquid in that recipe. Sometimes it's easier and cheaper to just use the original scratch recipes instead of doctoring up a boxed mix…in your case, 2 boxed mixes! After you added extra flour, sugar, coffee creamer, yogurt and everything else, you would have come out so much cheaper and had a better result with the real recipe.
I am sure it tasted great with all those bananas in it! I just think there was too much liquid and not enough flour to hold it together….I don't know. The ratios were just way off.
Try the scratch recipe!! I know you will LOVE it! It's very dense. You only need a really small piece of it, so a 9 inch round cake with the 3 layers will feed about 18 people, if not more.
Please try it and let me know what you think! This way you will know what a real Hummingbird cake is supposed to taste like! :o)