Preheat the oven to 350°F (175°C) and grease a 9x5-inch (23x13 cm) loaf pan. Line it with parchment paper for easy removal.

In a small bowl, combine the chopped apples with granulated sugar and cinnamon, then set aside.

In another bowl, stir together the brown sugar and cinnamon for the swirl.

In a large mixing bowl, beat the butter and sugar until light and fluffy. Add the eggs one at a time, then mix in the vanilla.

Whisk the flour, baking powder, and salt in a separate bowl. Add the dry ingredients to the butter mixture, alternating with the milk, and mix just until combined.

Spread half the batter into the prepared pan. Top with half the apple mixture and half the cinnamon sugar swirl. Repeat with the remaining batter, apples, and swirl.

Lightly drag a knife through the layers to create a ribbon of cinnamon throughout. Bake for 55 to 65 minutes, or until a toothpick inserted in the center comes out clean.

Let the bread cool in the pan for 15 minutes, then transfer to a wire rack to finish cooling completely. Once the loaf is mostly cooled, prepare the glaze by whisking together confectioners’ sugar, milk, and vanilla until smooth. Finally, drizzle the glaze over the top and slice to serve.