The oven temperature is critical when baking a cake, too hot and the top of the cake will begin to cook before the centre of the cake, forcing the cake mixture to rise up through the crust causing it to look like a volcano. If this happens when you first make a cake, make a note to turn the oven down 5 or 10 degrees next time. All ovens do vary in temperature so an oven thermometer can be useful if you think your oven is too hot.