posted by John .
1. Crisp Crackling Crusts
2. Crispy Crackling Crusts
(Which one is correct? Are both OK? What is the meaning of 'crackling'")
Both are correct.
Crackling implies a crispy texture. Here's the definition from Dictionary.com.
"to make slight, sudden, sharp noises, rapidly repeated."
When you eat these crusts, you crunch on them, making a slight, sharp noise with your teeth.