1. What does it mean?
In this expression, 빵 represents a sudden bursting sound and 터지다 means to burst. Together they describe laughter coming out all at once after a joke or an unexpected moment.
Also written or said as 빵터지다, 빵 터짐, 빵터짐, ppangteojida
2. The nuance
빵 here is not the noun meaning bread. Everyday forms include 빵 터졌어 for 'I cracked up' and 빵 터짐 in a caption. It describes the reaction, not whether a joke is objectively funny.
3. Examples
“강아지가 자기 꼬리를 보고 놀라는 바람에 빵 터졌어.”
I burst out laughing when the dog got startled by its own tail.
“그 대사를 너무 진지하게 읽어서 다 같이 빵 터졌다.”
They read the line so seriously that we all cracked up.
Sources
Study Korean: Korean language learning
KoreanClass101: Korean language lessons
References support the meaning and usage. Example sentences are written for NoCapWiki.