Preheat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and set aside.
In a large mixing bowl, whisk together the flour, sugar, baking powder, cinnamon, and salt.
In another bowl, combine the melted butter, eggs, vanilla extract, and milk. Mix until well combined.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Gently fold in the diced apples.
Pour the batter into the prepared loaf pan and spread it evenly.
Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted in the center comes out clean.
Allow the loaf to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.
To make the glaze, whisk together the powdered sugar and milk in a small bowl until smooth.
Drizzle the glaze over the cooled loaf and let it set before slicing and serving. Enjoy!