Preheat oven to 325 degrees.
Bake pie shell for 10 minutes.
While pie shell is baking, in a large mixing bowl, combine the pumpkin, evaporated milk, sweetened condensed milk, brown sugar, pie spice, cinnamon, salt, and vanilla. Mix powdered egg replacer with water according to instructions and pour immediately into the pumpkin mixture. Mix until just combined.
Pour filling into par-baked pie shell to rim. Place pie on a cookie sheet to make transferring back to the oven easier. Return to oven and bake pie for 60 minutes, or until the top appears to be set up. If the crust begins to get too brown, cover edges with foil or a metal pie shield to prevent burning.
Once baked, remove from oven and allow pie to cool. Top with Cool Whip before serving.