Preheat oven to 350 degrees. Spray a 9x5-inch loaf pan with non-stick spray.
Mix ⅓ cup brown sugar and 1 teaspoon cinnamon together in a bowl. Set aside.
Combine 1 ½ cups flour and 1 ¾ teaspoons baking powder in another bowl and set aside.
In another medium-sized bowl, beat together ⅔ cup granulated sugar, and ½ cup softened butter until smooth and creamy.
Add 2 eggs to mixer,one at a time, until blended. Then add and 1 ½ teaspoons vanilla extract and mix.
Add flour mixture into creamed butter mixture and blend well.
Mix ½ cup of milk into batter until smooth.
Pour half the batter into sprayed loaf pan. Sprinkle chopped apples with cinnamon and sugar and mix well, before spreading half on top of the batter layer.
Sprinkle half the brown sugar/cinnamon streusel on top of the apple layer.
Repeat this process all again with second half of batter, apples, and streusel on top.
Bake in the preheated oven until a toothpick inserted in the center of the loaf comes out clean, approximately 50 minutes.
Let loaf cool in pan for about 15 minutes before gently turning over to remove. Let cool on wire rack for about 30 minutes more before drizzling with apple cider glaze.
Store in an airtight container for several days.