1. Preheat oven to 350°F (175°C) and grease or line a 9×5-inch loaf pan.

2. In a small bowl, combine diced apples, sugar, and cinnamon. Set aside.

3. In a large bowl, cream together butter and sugar until light and fluffy.

4. Add eggs and vanilla extract; mix until combined.

5. Whisk together flour and baking powder, then gradually add to the wet ingredients, alternating with milk.

6. Pour half the batter into the prepared pan.

7. Top with half of the cinnamon-sugar apples and sprinkle with half the brown sugar-cinnamon mixture.

8. Repeat layers with remaining batter, apples, and cinnamon mix.

9. Using a knife, gently swirl through the batter to create a marbled effect.

10. Bake for 50–60 minutes, or until a toothpick inserted in the center comes out clean.

11. Let cool in the pan for 15 minutes, then transfer to a wire rack.

12. In a small bowl, whisk together glaze ingredients and drizzle over the cooled bread before serving.