You will never guess me, just cant be done

This is a quest, not one for jest, with a nod to the king of this answer. It wears a red crown, causes havoc in traffic, and hides which came first.

What’s abundant this time of year in Northern Hemisphere? Also Jon.

I’m cut into slices, yet I start as a whole. I’m round like a wheel, but I’m meant to be shared. Cheese is my blanket, sauce is my voice, and toppings are choices, some loved, some dared. What am I?

Don't let that orange thing from the fire get into your eye! Oh, and before I forget, what is that?