For a military soldier's birthday cake, some popular cake designs are the camouflage cake and the battlefield cake. Other army-themed cake designs are those resembling an army tank, aircraft carrier, battlefield helmet, a flag, a grenade, an army seal or anything related to the military.
To make a camouflage cake, prepare at least three shades of icing; green, tan and brown, for example. Then take a cake and cover it with the three shades of icing to make a camouflage design. Adding some toy army men, tanks or a helicopter on top enhances the design. Another very easy way to have a military soldier's birthday cake is to have the soldier's photo made into an edible image and placed on top of a cake with white frosting.