In heavy medium saucepan, combine unflavored gelatin, cinnamon, ginger, nutmeg and salt. Stir in sweetened condensed milk and eggs. Mix well. Let stand one minute. Over low heat, cook and stir constantly until gelatin dissolves and mixture thickens, about 10 minutes.
Remove from heat and stir in pumpkin. Mix well. Pour into prepared crust. Chill 3 hours.
This is a recipe my daughter gave to me. I have no idea where she got it.