Grease pie dish well, or line with parchment paper, and set aside.
With an electric mixer, cream butter alternative and sugar until light and fluffy. Beat in applesauce. With mixer on low, gradually add flour mixture; beat until combined.
Place half of the dough in the prepared pie dish and use your fingers to spread it evenly in a 1/4-inch layer on the dish. Add more dough as needed.
Bake, rotating halfway through, until edges are slightly golden, 10 to 15 minutes (depending on thickness of the crust). Allow to cool completely on wire racks.
Combine all pumpkin pie filling ingredients in a mixing bowl and whisk until smooth. Pour into prepared pie shell.
Bake at 350 F for 30 to 40 minutes. If you are concerned about the pie crust burning, wrap the edges of the crust with foil while baking.
Cool on a wire rack. The pumpkin pie filling will solidify and gel as it cools.