Preheat oven to 350 degrees F. Spray a 9x5-inch loaf pan with non-stick spray.(Or you can line pan with foil then spray with non-stick spray for easier removal.)
Mix the brown sugar and cinnamon together in a small bowl. Set aside.
In a large bowl, beat white sugar and butter together, using an electric mixer, until smooth and creamy. Beat in eggs, one at a time, until blended in; add vanilla extract.
In a separate bowl, combine flour and baking powder together with a whisk, then slowly pour this mixture into the butter mixture. Stir until blended. Slowly mix milk into the batter until smooth.
Pour half the batter evenly into the prepared loaf pan; then top evenly with half the chopped apples. Sprinkle half of the brown sugar/cinnamon mixture evenly over the apples. Lightly pat apples into batter.
Pour the remaining batter over the apple layer, then top batter evenly with remaining apples, then sprinkle remaining brown sugar/cinnamon mixture. Lightly pat apples into batter; swirl brown sugar mixture through apples using knife or spoon.
Bake, uncovered, for 50 to 60 minutes or until a toothpick inserted in the center of loaf comes out clean.
To make glaze: mix powdered sugar and milk together until combined. Let bread cool for at least 15 minutes before drizzling with glaze. Slice, serve and enjoy!
