Prepare your double pie crust of choice.
Preheat the oven to 350 degrees.
Thoroughly wash and pat dry your raspberries.
In a medium bowl, combine the sugar, corn starch, lemon zest, lemon juice, and vanilla.
Add in the raspberries and gently fold. It is okay for some of the raspberries to break, but do not try to mash the raspberries down.
Line a 9" pie plate with one pie crust. Poke a few holes in the bottom of the pie crust using a fork to prevent air pockets from rising up during baking.
Pour the raspberry filling mixture into the pie crust.
Top with the second pie crust, or use a lattice technique to decorate.
Bake for about 1 hour and 30 minutes, or until the filling is thick and bubbly, and then crust is golden brown.
Remove from the oven and let cool for 3-4 hours, or overnight.