First make the topping. Put the lactose free butter, double cream and maple syrup together in a small pan and stir over a low heat until well mixed. Bring to the boil, simmer for 1 min, then pour into the base of a buttered 900ml pudding basin.
Sift the gluten free flour into a bowl with the cinnamon and nutmeg. In a separate bowl, beat the lactose free butter with the sugar and maple syrup until light and fluffy.
Beat in the egg a little at a time. Fold the dry ingredients into the creamed lactose free butter and egg mixture, adding the lactose free milk to give a soft dropping consistency.
Spoon the mixture into the basin, then cover with greased greaseproof paper and foil, making a pleat in the centre of both. Tie securely with string.
Steam the pudding for 1½ hrs, checking regularly to make sure that the pan doesn’t boil dry. Turn out and serve with extra warmed maple syrup and a generous helping of lactose free double cream.