Each row, column, and region contains the digits 1-9 exactly once plus three π symbols. There’s a printable .pdf file here.
As a bonus, if you send a correct solution in to Brainfreeze puzzles in the next couple months, you’re eligible for a drawing for their book on Color Sudoku! More details are on their website.
Happy Pi Day Week!
Edited 10/31 to add that the solution hasn’t been posted on the Brainfreeze site yet, but since it’s well past the contest deadline we approved a comment that has the solution (below).