Jill - from Bridgewater, NJ
If you cannot return a partially baked cake or bread to the oven immediately, you should throw it away because of the threat of food spoilage and/or contamination. Also, the leavening in the unbaked batter will lose its strength over time, so the center which didn’t bake will most likely not rise as high as the rest of the cake. The best choice is to start over!