Pi

Two letters

Infinite amount of numbers

Pie

Three letters

Infinite amount of food

Pi

3.141592...

Pie

A circle made out of baked dough with fruit filling.

Pi

Pie

3.14

🍰

Combine them together and you get...

3.14e

The best of both worlds.

Author's Note:

Yeah I know what you are thinking,

'I'm getting hungry right now.' and 'This is a really good poem.' Hah. I know this is not really a poem, but yeahhh.