Have you ever thought as to why cakes are round? I personally prefer square cakes as they are easier to cut. Raising twin sons and baking cakes all the time, I found baking a square cake was so practical. There was no wastage and no quarrels as to who got the largest slice. It is also more economical.
In ancient times, some civilizations baked cakes as an offering for their Gods and Spirits. A round cake epitomizes the cyclical nature of life, as well as the sun and moon. Also, this is the explanation as to why cakes are served at special occasions to indicate the cycle of life.
A practical answer is that ancient breads were shaped by hand and baked in low, shallow pans.
A little more information. The circle (the most spontaneous of natural shapes) best represents the Hindu universe because the Hindus see the world as being timeless, cyclical and infinite.
The universe is the medium through which the divine presents itself. It is the window to the divine. – Devdutt Patnaik
Then throughout the ages, the wearing of a ring has become symbolic of commitment and the promise of eternal love.
God is a circle whose center is everywhere and whose circumference is nowhere. – Hermes Trismegistus
Apply the word circle to yourself and remain in the presence of the divine.
Aim Hrim Klim