Pre-heat oven to 350F (180C). Grease and flour a 9x5 inch (23x12cm) loaf pan.
In a medium bowl cream butter, add sugar and cream well, then add the egg, beat for approximately 1 minute.
In a medium bowl add flour, salt, soda and cinnamon, whisk to combine, then fold in the diced apple until combined.
With a wooden spoon add the flour mixture, alternately with the milk (in 3 parts, ending with the milk) to the creamed mixture. Mix just until combined. Batter will be lumpy. Spoon into the prepared loaf pan, top with either the cinnamon topping or crumb topping and bake approximately 55 minutes.
FOR THE CINNAMON TOPPING
In a small bowl mix well the sugar and cinnamon.
FOR THE CRUMB TOPPING
In a medium bowl mix until well combined the flour, sugars (if you prefer you can use 4 tablespoons of granulated sugar) and cinnamon. Add the butter and with a fork mix until coarse crumbs appear.
Notes
For room temperature ingredients remove from the fridge 30-60 minutes before using.