Try reducing the amount of yeast. A low oven temperature or an uneven temperature can lead to a poorly shaped loaf. Use a thermometer when in doubt. A 10 minute rest period will make dough much easier to handle and shape properly. Use a rolling pin.
Excess flour can lead to a stiff dough that cracks.
However, if you follow this recipe , the piercing of the loaf will allow the cracking to occur on the bottom of the loaf, out of sight. Flour should be stored in a cool, dry place and used within one year. Use an oven thermometer to assure the oven is the correct temperature. Test for double in size using the finger-tip test. Insufficiently risen dough can crack.