パキッ

adverb taking the 'to' particle

with a snap; with a crack

Mimetic word describing a sharp, dry breaking or snapping sound, often of something thin or brittle.

• 枝えだがパキッと折おれた。

  The branch snapped with a crack.

• クッキーをパキッと割わった。

  I broke the cookie with a snap.