Well if it was crust <pie or whatever you think it is> it does fit in some of the riddle.
With my power I stop bread's spread-<What power? But it does stop bread from rising and spreading.>
I am even that on you tread-<You tread on the Earth's crust or are we just having illusions?>
Flip me over and you shall sing-<In some cultures they eat pies upside down and sing in ?joy?.>
Fervid praises fit for a king.-<Have you ever heard that one poem? The one of blackbirds in a pie?>
ireadofit