How did round planets form from the explosion of the Big Bang?

In the beginning there was a cosmic egg that hatched.

For your information, Cosmic egg was re-introduced by into cosmology albeit under the name of primaeval atom by a catholic priest Abbe Lemaitre who was the egg the Big Bang hypothesis hatched from.

Apart from adhominems added, your post grapples with a single quote out of context.

Also, when you call what I write a lot of nonsense, be more specific and attach a bit of your own good sense next to it so that the difference should be apparent.

Those books unlike ancient mythologies might not mention literal eggs, yet the underlying logic and all the train of thought and chain of associations behind the ancient ideas and their modern version is the same. An egg cosmic or otherwise is something relatively small compared to a bird species or the entirety of the universe. The hatching of it is a single event that had allegedly occurred at a certain point of time giving birth to many subsequent events to which all of those events could be traced. A some kind of calendar of those chains of events or a timescale is always present and so on.
Now whether in the modern versions this is called a primeval atom or Planck particle, the fundamental idea is the same. One primeval atom splits into many at a certain point of time and the resulting many, in their turn split in many more as a function of time. That could be called an expansion of the egg. Hatching of an egg is a kind of bursting. An explosion of sorts. Similar in a way to an explosion of the bomb Gamow was involved in designing. The model is the same, only the length of time-line and the pretended precision of measurements would vary.