From Richard Creel's book about divine impassibility:
"God does create ex nihilo in the sense that what he creates he does not create from antecedent individuals or matter" (page 72).
On the same page, Creel insists all that creation requires is an act of divine volition. Jehovah is unlike Plato's Demiurge (see Timaeus) that brings the cosmos into being by impressing form on recalcitrant matter.
In Basic Theology, Charles C. Ryrie supplements Creel's account by pointing out that God creates ex nihilo by dint of his "omnipotent resources." That is all God needs to create the universe--his almighty power and only his almightiness.