spicer

No — say "spicier". Spicier is already a comparative form; adding 'more' creates a double comparative error.

Definition

adj. more full of spice or having a stronger, hotter taste than something else. You use this to compare two foods that have a kick.

adj. the comparative form of 'spicy'; containing more spice or producing a more pungent, piquant sensation on the palate.

Comparative adjective — typically followed by 'than' when comparing two items.

more spicier

spicier

Spicier is already a comparative form; adding 'more' creates a double comparative error.