Soak 4 envelopes of gelatin in 1 cup of cold water. Set aside. In a saucepan, combine 4 cups sugar with 1 cup of chilled water. Stir over medium heat until sugar crystals dissolve, and add gelatin from packets. Bring to a boil & stir. Once it's boiling, remove from heat, pour into a bowl & let cool. Add ½ tsp salt & 3 tsp vanilla extract. Mix with an mixer until doubled in thickness. Pour into a greased glass baking pan & let set. Cut into shapes using cookie cutters & dust with powdered sugar.