I would like to know why a lot of my cakes sink in the middle. I guess it's because the middle is still not cooked enough. Yet even when I bake them for longer than the recipe states I still often have problems with sinking. The temperature of my oven has been tested and is accurate. Is there anything I should do differently in the mixing process? Many thanks Rachel
When you are checking the temperature of your oven it is useful to do it several times with the oven thermometer in several positions in the oven. Ovens can have hot and cold spots and if the cakes are sitting over a cold spot then the centres could take longer to cook, or may not cook properly. If the cake takes too long to cook then the raising agent can also stop working (the chemical recation which produces carbon dioxide bubbles will only last so long), causing the cake to sink back if it has not fully set.
Also make sure that the oven is properly preheated before the batter is mixed. If the cake batter sits around too long before being baked then again the raising agents will finish working before the cake is baked and the centre will sink back. Also make sure that you are measuring the raising agents carefully (use a proper measuing spoon) as too much can cause the cake to rise very high and very quickly but with a weak structure, so it will sink back again as it comes out of the oven.
Whilst you will need to check that the cake is baked, don't open the oven door too early. A blast of cold air, generated by the door opening, can also cause the unset centre of a cake to sink. If you need to rotate the cake pans during baking then wait until the cakes have baked for around 3/4 of the baking time and are almost fully set. Avoid opening and closing the oven door too sharply and move the pans around gently to minimize the risk of sinking.