In a medium saucepan, combine unflavored gelatin, sugar, salt, and spices, whisking until well blended. Gradually stir in the milk, followed by the egg yolks and canned pumpkin. Cook over medium heat, stirring constantly, until thickened.

Remove from heat and cool to room temperature, then transfer to the refrigerator for about 30 minutes or until partially set.

In a mixing bowl, beat the egg whites until soft peaks form. Gradually add the remaining sugar while whisking until stiff peaks form.

In another bowl, whip the heavy cream until stiff peaks form. Set aside.

Gently fold the pumpkin mixture into the beaten egg whites, then fold in the whipped cream until combined without streaks.

Pour the mixture into a pre-baked pie crust, smooth the top, cover loosely with plastic wrap, and refrigerate for at least 4 to 5 hours or overnight.

Serve topped with whipped cream and a sprinkle of nutmeg.