Rosalie - from Aguadilla, Puerto Rico
Sometimes a cake will sink in the middle because it is underbaked. Before removing your cake from the oven be sure to test it with a toothpick or cake tester. If the toothpick comes out clean then your cake is done. If it comes out with batter on it, continue baking and check again in a few minutes. Also make sure your oven is working properly. Place an oven thermometer in your oven to make sure that it is calibrated correctly.