First place the tin of black treacle (without a lid) in a saucepan of barely simmering water to warm it and make it easier to measure (see Traditional Oatmeal Parkin recipe).
Next prepare the dates and pecans. The nuts should be chopped fairly small and the dates should be chopped into equally small pieces.
Now to make the cake mixture: place the butter, black treacle and syrup in a large saucepan and melt them together over a gentle heat. Remove the mixture from the heat, let it cool for a few minutes, then mix in the milk.
Now beat the eggs and add those to the syrup mixture as well.
Next sift the flour, spices and bicarbonate of soda into a bowl and gradually whisk the syrup mixture into the dry ingredients, bit by bit, until you have a smooth batter. Then lightly stir in the pecans and about two thirds of the dates, and pour the mixture into the prepared tin.
Now lightly drop the rest of the dates on the top, pushing them gently in with a skewer. I find adding this amount of dates last of all gives a better distribution of fruit as the mixture is a fairly slack one.
Place the cake on a lower shelf so that the top of the tin is aligned with the centre of the oven and bake it for 1½ hours to 1 hour 50 minutes by which time it will have a very rounded, slightly cracked top.
Cool it in the tin for about half an hour before turning it out.
To make the icing: in a small saucepan melt together the evaporated milk, brown sugar and butter, then simmer the mixture for 5 minutes.
After that tip it into a bowl and leave it to cool.
Then sift in the golden icing sugar and whisk everything together till smooth. Finally, using a palette knife, spread the icing all over the top of the cooled cake.
Keep the cake in a tin in its liner – and it does seem to improve if kept for a couple of days before eating.