Prepare the Oven and Pan
Preheat oven to 350°F (175°C). Grease a 9×5-inch loaf pan with nonstick cooking spray.
Mix Cinnamon Sugar and Apples
In a small bowl, combine brown sugar and cinnamon. In another bowl, toss chopped apples with 2 tablespoons granulated sugar. Set both aside.
Prepare the Batter
In a large bowl, cream butter and remaining granulated sugar until light and fluffy. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
Combine Dry Ingredients
In a separate bowl, whisk together flour, baking powder, and a pinch of salt.
Alternate Mixing
Gradually add the dry ingredients to the butter mixture, alternating with milk. Begin and end with the dry ingredients. Mix until just combined.
Assemble the Bread
Pour half the batter into the loaf pan. Sprinkle with half the cinnamon sugar and half the apples. Repeat layers with remaining batter, cinnamon sugar, and apples.
Bake
Bake for 50–60 minutes, or until a toothpick inserted in the center comes out clean.
Cool and Glaze
Cool in the pan for 10 minutes, then transfer to a wire rack. Mix powdered sugar with enough milk to form a drizzle and pour over cooled bread.
Serve
Slice and enjoy as a sweet breakfast, snack, or dessert.