Preheat the oven to 350°F. Lightly grease a loaf pan and set aside.
In a medium bowl, mix together the salt, baking powder, flour and cinnamon. Set aside.
In the bowl of a stand mixer, cream together the butter and both the sugars until light and fluffy. Add in the eggs one at a time, mixing after each addition. Mix in the vanilla.
Alternate between mixing in the dry ingredients and the milk into the sugar mixture until just combined. Fold in the apples.
Pour the batter into the prepared baking pan and set aside.
In a small bowl, mix together the topping ingredients. Sprinkle on top of the batter.
Bake in the preheated oven for 50-55 minutes, or until a toothpick inserted comes out clean.
Allow to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.