To bake a perfectly level cake every time- use baking strips around your cake pans. These can be purchased, but it is easy to make your own.

Roll out a length of paper towels to fit the circumference of your cake pan.
( plus a little extra for overlap) Then fold the towels lengthwise, making the width of the folds the same as the height of your pan. Now wet this long strip of paper with a good amount of water and then encase it in the same length of tin foil. Now wrap this strip around your cake pan and secure with tape or twist the ends together. This is done before baking and left on during baking. This prevents the center of the cake from rising up, cracking and falling.