I've been reading and am new here. I've been baking for years and wanted to try some of the cool techniques found here for making a cake mix taste homemade, and moister.

Well....to a normal cake mix with pudding (I've tried all three brands!) I added just a spoon of sour cream, 1/2 box pudding, and one extra egg. I also used creamer and milk instead of water.

Each time I bake the cake, it sinks -big time- in the center!
I have had trouble adjusting my oven temp since I bought a thermometer...it seem never to stay at anytihng but 350. If I turn it down it goes down to 300. I bake it for 45-60 minutes.

Even so, the cakes are so moist that they are almost wet to the touch and taste great, but they are un-sellable. There HAS to be the perfect combination of additions to make it right. What am I doing wrong?

I honestly don't know. Mine don't sink as a rule. Have you tried not doctoring in a while? You have verified it's not your oven baking unevenly?

Well, I tried decreasing the sour cream because one recipe I had called for an entire cup. I also move the racks in the over to different levels thinking that it might help. I used Wilton even baking strips also. I waited 20 minutes before opening the oven to check - because mine bakes hotter inthe back so I have to turn it "gently". Never seemed to have trouble before this weekend!

Maybe its a full moon somewhere. LOL