Castleton Vicarage Cake (very crumbly!)

Ingredients

1 lb/450g self-raising flour (or the same of plain flour plus 1 tsp of baking soda) – but see note
12 oz/340g of demerara sugar
1 lb/450g sultanas or mixed dried fruit
4 oz/115g of candied peel (or the same of more sultanas)
12 oz/340g of butter
1/2 pint/280cc milk - will need to be hot but not boiling

1 tsp mixed spice
2 tbs brown sugar mixed with ½ tsp cinnamon

Method

Preheat oven to 170C/350F. Grease two loaf tins and line with parchment/greaseproof paper.
Mix all the dry ingredients together in a large bowl. Add butter that has been cut into walnut size lumps and stir these through. Then, pour HOT milk over the whole. Stir thoroughly with a wooden spoon, and then scoop the thick batter into your tins. Top with the cinnamon/ sugar mixture & lightly pat it in with the back of a spoon.

Baking time is approximate. I baked two loaf tins of this cake; they took roughly 60 minutes, but if you use one large cake tin it will take longer. Start checking on it after an hour, doing the usual “clean skewer” test. 

Note:  I recently read that substituting strong flour for the plain flour results in a less crumbly cake, but it may need slightly more liquid in the mix.  So ...
I tried substituting 50g s/r flour with 50g strong flour, & adding half a tsp baking powder.  No discernable difference.