Preheat oven to 350°
Cream butter and sugar using a hand mixer or stand mixer.
Add the eggs to the mixture and beat well.
Peel, pare and chop apples until you have 1 3/4 cups (I used 1 large Golden Delicious, but use as many of any kind of apple as it takes)
Combine flour, baking soda and salt in a separate bowl.
Mix vinegar and milk in another bowl. The mixture will curdle a bit! Don't worry, it's supposed to. If you have buttermilk on hand, you can use that instead.
Add the dry ingredients to the creamed butter and sugar alternately with the milk mixture. Start and end with the dry ingredients. (In other words, add 1/3 of the dry ingredients to the creamed mixture. Mix. Add 1/2 the milk mixture. Mix. Add another 1/3 of the dry ingredients. Mix. Add the rest of the milk mixture. Mix. Add the last of the dry ingredients. Mix until fully combined.)
Stir in apples and nuts and combine with a spoon or spatula, not your mixer.
Pour batter into a greased loaf pan.
Create the topping by combining the flour, sugar, cinnamon and butter (melted)
Spread the topping over the batter (it doesn't have to be perfect!)
Bake at 350° for about 1 hour, or until cooked through.