Ellie Kemper -- Good Genes Or Good Docs?!

Ellie Kemper's good looks are truly something to celebrate!

Here is a 28-year-old version of the comedic actress looking bangin' at a party in Los Angeles back in 2009 (left). This was the same year Kemper landed the role of Erin Hannon on NBC's "The Office".

And, 12 years later ... she has a lot to celebrate -- including her 41st birthday which is this weekend -- she's been sharing snaps of her life on Instagram and posted a pic earlier this year showing off her famous smile (right).

The talented star has since worked on a number of projects, including her show "Unbreakable Kimmy Schmidt".

She gets the Dundie for ageless looks.

The question is ...