Pre-heat oven to 190c. Line and grease a Swiss roll tin, or sided Baking Tray.
Mix together the cooked mashed pumpkin with the Lemon Juice.
Mix together all the dry ingredients, flour, baking powder, sugar, salt, nutmeg, cinnamon
Beat the eggs well and then gradually add the sugar and continue beating till they are thick and foamy - preferably beat for several minutes.
Into the beaten eggs and sugar stir through the pumpkin mash and then follow this with stirring through the dry ingredients.
Spread into your flat tin and bake in oven for 15 minutes.
Bake just enough so that it is springy to the touch.
Remove from oven and turn out onto either a tea towel or baking paper sprinkled with Icing sugar.
Leave to cool for a couple of minutes then roll up in the tea towel/baking paper.
When cool fill with whipped cream - jam also as you wish.
For something more savory use blended sour cream/touch of cream cheese/vanilla.
Unroll when cooled - spread filling and roll-up again.
Dust with icing sugar.