In a small bowl, combine sugar, flour, cinnamon and salt, and stir with a fork to mix well.
In a medium bowl, combine the figs with the dry ingredients and toss to coat evenly.
Pour the figs into the prepared pie crust. Pour the lemon juice over the figs mixture and dot with the bits of butter. Cover with the top layer of crust and press the edges down to seal.
Bake for 10 minutes and then reduce the heat to 350 degrees F/175 degrees C. Bake until filling is thick and bubbling and crust is golden brown, about 45 minutes. Transfer to a cooling rack and let cool to room temperature. Dust with powdered sugar before serving.