In a medium bowl whisk together the condensed milk, pumpkin pie spice, eggs, pumpkin puree and salt until well combined. Be sure the eggs are well incorporated.
Sprinkle 1 Tablespoon flour inside the pie crust and spread it around the cover the crust. Poke holes in the bottom and sides of the crust with a fork.
Bake for 15 minutes at 425ºF then reduce the oven temperature to 350ºF and bake for another 30 to 40 minutes or until a knife inserted about 1" from the edge of the crust comes out clean.