Knock knock. Who's there? Fig

Fig who? Fig-ure it out yourself!

Knock knock. Who's there? It's me.

It's me who? It's me, and I'm not here for a joke. I actually need to borrow a cup of sugar.

Knock knock. Who's there? Lettuce.

Lettuce who? Lettuce *pray* this joke *grows* on you, I've really *leafed* through a lot of ideas to *cultivate* this *gem* just for you, so please *romaine* here and enjoy!

Knock knock. Who's there? Donut.

Donut who? Donut even think about glazing over this punchline; it's sure to be sweet!