Preheat oven to 350 degrees and spray a 9x13 inch pan with cooking spray.
Place flour, sugar, and salt in a food processor and pulse until combined. Add butter and continue to pulse until the mixture resembles coarse meal. Gently press the mixture into the bottom of the prepared pan, do not go up the sides. Bake 10 minutes or until golden brown. Cool completely.
In a medium bowl, beat cream cheese until creamy. Add the sugar and beat until well combined, 2 minutes. Add the pumpkin puree, vanilla, pumpkin pie spice, salt and beat to combine. Add the eggs, one at a time, beating well after each addition. Pour pumpkin cheesecake over cooled crust and spread evenly with a rubber spatula. Bake 40 minutes or until the edges are firm but the center still slightly jiggles. Cool completely. Once cool, cover in plastic wrap and refrigerate 2 hours or overnight.
In another medium bowl, cream the butter and cream cheese. Add the vanilla and sugar and continue to beat until light and creamy. Spread over chilled cheesecake.
Serve immediately or store in an airtight container in the refrigerator, up to 3 days.