Pi Day is held to celebrate the mathematical constant π(pi) (in the mm/dd date notation: 3/14), being a programming geek I have to celebrate this day :)
To make my Pi pies I use a simple recipe for the pie, and then use a paring knife to create the Pi symbol.
The initial steps are to prepare your pie dough, then roll it out to fit the pie pan shell. With the pie shell created you then fill the pie with your choice of fruits & berries (I chose to make a Cherry and an Apple pie this year). After filling the pie shell you can then roll out a second pie crust to cover the pie. Now the fun part begins; use the paring knife to carefully carve out the shape for the Pi symbol. You can do this freehand or use a paper cut out trace the image on to the pie crust before carving.
With the Pi symbol carved into the pie you can now finish the pie edge with a simple crimping using a fork pressed lightly to the edge.
I hope everyone has a fun Pi day this year!