Place a sheet of parchment paper on a large plate. In a medium-large skillet/saucepan, bring the brown sugar, salt, and water to a boil over medium-heat heat. Stir and cook for about 3 minutes until the liquid reduces. Add in the pecans, stir to coat, and keep cooking until the liquid becomes thick, syrupy, and the water mostly all evaporated. Transfer the candied pecans to the parchment lined plate and cool while you begin to make the cake and frosting.