Preheat oven to 350 degrees. Grease and flour 9x13 baking dish. Combine pumpkin, sugar, evaporated milk, salt, pumpkin pie spice and eggs in a large bowl and mix thoroughly. Pour pumpkin mixture into baking dish. Sprinkle yellow cake mix evenly on top of pumpkin mixture. Top with chopped pecans. Drizzle two sticks of melted butter over pecans. Bake at 350 degrees for 1 hour or until golden brown. Serve with a dollop of Cool Whip and sprinkle of cinnamon.