Cut the stems off of each end of the plantains. Use a small knife and cut a vertical line from tip to tip of the plantain, cutting through the skin but not through the plantain. Turn the plantain over, and cut the same line down the back. Peel the skin off of the plantain. It should come off in two halves.
Cut the plantain into about 1-1 ½ inch pieces.
In a cast iron skillet, heat about ½-¾ inch of oil, enough to cook about half of the plantain at once. Your oil should be heated on low-medium heat, so that your plantain can cook without burning. It should be hot enough that when you drop your plantain in, it starts to bubble in about 5 seconds.
Place the plantains in the oil, cooking for about 5 minutes or until the surface starts to brown. Use tongs to flip the plantains over and cook on the other side. Remove to a paper towel lined plate.
Grease the bottom of a glass with nonstick spray and use the glass to smash the plantains, reapplying nonstick spray when necessary.
In a small bowl, combine ½ cup warm water with 2 tbsp salt. Stir until salt dissolves.
Quickly dip each smashed plantain in the salt water and leave to dry on paper towel-lined plate again.
Once dried, add the plantains back into the hot oil, and fry for another 3-5 minutes. Remove and place on paper towel lined plates. Sprinkle with salt. Enjoy!