Preheat the oven to 180C/gas 4/ fan 160C. Butter and line the base and two long sides of a 1.5kg loaf tin with a strip of baking paper.
Mix the butter, honey and egg and stir in the pumpkin or squash. Then mix in the sugar, flour and ginger.
Pour into the prepared tin and sprinkle the top with the demerara sugar. Bake for 50-60 minutes, until risen and golden brown. Leave in the tin for 5 minutes, then turn out and cool on a wire rack. Serve thickly sliced and buttered.