The phrase "cracked open" refers to the act of breaking something open, often with force or pressure. When searching for synonyms to describe this action, a few options come to mind. "Pried open" suggests the use of a tool or lever to force something apart. "Split open" also implies force, but with a focus on the item being torn apart. "Splintered open" indicates that the object broke into many small pieces. "Burst open" connotes a sudden and explosive opening, like a burst balloon. Overall, these synonyms offer a range of options for describing the act of cracking something open.