Preheat the oven to 170° C / 338° F. Grease and dust one 4" × 8" loaf tin well.
Cut, peel, de-seed, chop and weigh the pumpkin. Steam or boil the pumpkin with very little water until soft. In a bowl, mash the boiled pumpkin with a fork and set aside for later.
In a bowl, combine the flour, salt, bicarbonate of soda, nutmeg and cinnamon. Whisk well until combined and set aside.
In a large bowl, beat the sugar and butter/margarine using an electric mixer or a whisk. Beat on medium speed until just blended.
Add in the egg and beat well until light and fluffy. Mix in the mashed pumpkin. The mixture will look grainy
Add the flour mixture and mix on low speed until combined.
Turn the batter into the prepared tin and spread it out. Bake for 1 hour or until a cake tester comes out clean. Let the cake cool in the tin for about 5 Minutes then turn on to a rack to cool completely.