I have a gas oven. I have raised a question regarding it before, Baking in gas oven does not brown the top. This time when I baked I placed a aluminum foil in bottom rack and baked 2 same size cake on the top rack. The cake on the left baked evenly and was fine. The cake on the right though browned more sank in the middle on cooling.
I had heated the oven to 180 C and baked the left cake for 30 minutes and since it got baked I removed and shifted the cake on the right in the middle as it was wobbly in the center. I baked it for 5 minutes more and then took it out. It looked fine first but when cooled it sank in the middle. What could have gone wrong here? How can I prevent it?