Preheat oven to 350°F degrees.
Grease your 9x5 inch loaf pan thoroughly.
Mix flour, sugar, baking powder, cinnamon, salt together.
Combine melted butter, egg, and milk separately.
Pour wet ingredients into dry ingredient mixture.
Fold in diced apples gently with spatula.
Pour batter into prepared loaf pan evenly.
Bake for 50-60 minutes until golden brown.
Cool completely before removing from pan carefully.
Mix powdered sugar, milk, vanilla for glaze.
Drizzle glaze over cooled bread generously.