There are few possible reasons for a cake to have a hump and/or is cracked on top.
1. Too much of raising agent
in the cake. Make sure of measuring the ingredients precisely and/or check the recipe.
2. Your cake pan was too small
for the recipe. Use a larger pan.
3. The temperature of the Oven was too high
causing the top to cook faster in a shorter span leading to uneven cooking. Use Oven thermometer.
4. The cake was baked on too low or high of a rack
. Cakes are better baked in the middle of the oven.
5. Opening the Oven door
frequently. This causes temperature in the oven to drop causing uneven cooking.
You might be interested in:
1. Cake Recipes
2. Eggless Cake Recipes