Sunken Cakes

Our answer

Most cakes will sink back slightly as they cool but if the cake is sinking dramatically on cooling and leaving a crater in the centre of the cake then there are two likely causes. The first is that the cake hasn't quite fully baked in the centre and as it hasn't fully set then it will collapse as the cake cools. When checking to see if a cake is properly done then first carefully and lightly press the top of the cake - it should feel firm to the touch and not squishy. Also insert a skewer, cake tester, cocktail stick (toothpick) or the tip of a thin knife into the centre of the cake, when it comes out it should be clean.

The second possibility is that there may be too much leavening (baking powder/bicarbonate of soda/baking soda) in the cake, causing it to rise too much in the oven. This stretches the glutens in the flour too far and they can't hold as the warm air trapped inside them cools down. If the cake is rising very spectacularly then this may also be an indication that there is too much leavening. Try to measure baking powder and bicarbonate of soda with a set of proper kitchen measuring spoons and make sure the spoonfuls are level. Bicarbonate of soda tends to be very active so reduce this slightly if it is used in the cake.