Remove the skin and seeds from the sweet pumpkin, then cut it into suitable pieces.
Place the sweet pumpkin in a steamer and steam until soft.
Once steamed, let the pumpkin cool, then blend until smooth.
Mix the pumpkin puree with milk, heavy cream, and sugar.
Pour the mixture into a bowl and heat gently over low heat, stirring continuously.
Soak gelatin in water, then add it to the warm pumpkin mixture and stir until fully dissolved.
Pour the finished mousse mixture into cups and let set in the refrigerator for 2-3 hours.