- Oven too hot: A cake pan that’s placed too close to the top heating element, or in an oven that’s too hot, will cause the cake to form a top crust early. This will crack as the inside of the cake continues to cook and rise, pushing upwards. To prevent this, set the cake pan on a rack in the lower half of the oven. Use an oven thermometer to check the internal oven temperature. - Wrong pan size: Using a pan size that's too small can cause the cake to crack as well. Ideally, the batter should fill no more than two-thirds of the pan. Use the pan size specified, or a cake pan of almost equivalent capacity.