This is DE-LI-CIOUS!!! Quick troubleshooting question please for my next one though because my cake sunk in the middle a bit after it came out of the oven. I opened the oven once about 30 min in to bake time to rotate pan - could this be enough to cause it to fall? I don't think I over-mixed the batter and used a 9in cake pan. I just bought another oven thermometer to make sure my oven is at the right temp. Thanks in advance for any assistance.