A cake can sink in the middle for several reasons. Paying attention to the following details should prevent the cake from sinking.

Oven heat should be accurate: a variance of 25oC can affect the success of the baking. Use an oven thermometer, which will quickly tell you whether the temperature in your oven agrees with the setting. If it doesnt, adjust the oven accordingly.

Bake cakes on the centre shelf of the oven, as this is generally the best position with the most stable temperature. Too hot an oven browns the cake too quickly on the outside leaving the centre uncooked.

Do not be tempted to open the oven door until at least half way through baking. The sudeen cold draft can make the cake sink right before your eyes.

Cakes should be tested a couple of minuted before the end of the baking time to ensure that they are cooked. Use a long wooden cocktail stick or skewer and stick it gently into the center of the cake. If it comes out clean, the cake is cooked, If it is coated with a gluey batter, it needs to bake for at least five or 10 minutes longer. Another sign that a cake is done is when the sides of the cake leave the sides of the pan. TO further ensure that it is cooked, lightly touch the top of the cake. If it springs back leaving no imprint, the cake is ready.

A great one on cake recipe.

More low carb recipe.