Preheat the oven to 180*C/350*F/ gas mark 4. Butter an 8 inch cake tin with a removable bottom and line with parchment paper on the bottom.
Whisk the melted butter together with the milk and the egg. Sift the flour, sugar and cinnamon into a bowl. Make a well in the middle and then add the liquid ingredients all at once. Mix together to make a smooth thick batter and then spread it into the prepared pan. Drop the cherries on top, pressing them down just slightly.
Whisk together the flour, cinnamon and sugar for the crumble topping. Rub in the butter with your fingertips until the mixture is all crumbly. Sprinkle this evernly over top of the cherries.
Bake in the preheated oven for 30 to 35 minutes, until well risen and golden brown. A toothpick inserted in the centre should come out clean. Remove from the oven and allow to stand for at least ten minutes before removing from the pan to a wire rack to finish cooling. Dust with icing sugar if you wish and serve, cut into wedges with some cream for pouring if desired.