Combine water and vanilla in a separate bowl, pour over pumpkin and mix.
In another small bowl, combine the cinnamon, pumpkin pie spice, sugar, salt, and flour. Pour that over the pumpkin and again mix it thoroughly, covering all slices.
Dump pumpkin slices into pie crust.
Plop globs of butter on top of the pumpkin and cover with pie crust top.
Bake at 350 for 1-1 1/2 hours, until the edges are just starting to brown.