Cut the pumpkin into chunks and boil in a large pan of water for 15 minutes or so until very soft. Drain well and then leave on a plate for a few minutes for the excess water to evaporate. Put it into a bowl and mash very well. You should get about a cupful of mash.
Add the flour, bicarbonate of soda, eggs, ½ teaspoon of salt and a couple of grindings of pepper and mix it all together well. Mix the sugar and cinnamon together on a flat plate.
Heat enough butter in a non-stick frying pan to just cover the bottom. When it sizzles, turn the heat to medium and dollop in a few large tablespoonfuls of the pumpkin mixture, letting them settle into fritters. Don’t touch them until they have set, with some holes appearing on their tops and their bottoms are golden brown. Swiftly flip them over with a metal spatula and cook until the new bottoms turn golden. Lift them out onto a plate lined with kitchen paper to soak up the oil, and then pat them richly on both sides in the cinnamon sugar. If the butter looks dark and as if it’s starting to burn, wipe out the pan with kitchen paper and add fresh butter. Carry on frying the rest, adding fresh butter as needed.