What is All Over It Like A Donkey On A Waffle?
To be completely on top of something, much as a donkey, when standing over a waffle, covers it entirely.
"Oh, that website you wanted me to finish? I'm all over it, like a donkey on a waffle."
To make an act one's top priority, much like scarfing free breakfast would be for a donkey, were it confronted by an unattended waffle. Usage of the phrase implies some amount of immediacy or urgency to the performance of the act.
Boss: Can you get that done by noon?
You: I'm all over it like a donkey on a waffle.
Boss: Hell yeah.