Oven temperature.
Pan too small/too much batter per pan.

Batter unevenly distributed between pans.

Batter unevenly distributed between pans. Fill pan about 1/2 full with batter.   Batter should measure approximately 1 inch in a layer pan and 2 1/2 inches  in a bundt pan.

Too much liquid.

Oven or racks not level.

Pans not placed in center of oven.

Cake Sticks to Pan/Difficult to De-pan

Not using pan grease.

Cooled improper length of time. (If cake is still hot and tender, it will break easily.

If too cold, the shortening begins to harden and can "glue" the cake to the pan.

Cake not loosened with knife or spatula before removal.

Cake Split/Cracked

Not enough batter per pan (use about 3/4 inch to 1 inch batter per layer pan and 2 inces to 2 1/2 inches batter per bundt pan.

Cake stored at too warm a temperature.