Preheat your oven to 350°F.
Grease your loaf pan with butter.
You can also use cooking spray.
Chop your apples into small pieces.
Mix them with sugar and cinnamon.
Set this bowl aside for later.
Beat butter and sugar until fluffy.
Add eggs one at a time.
Stir in vanilla extract.
Mix flour, baking powder, and salt together.
Add dry ingredients to wet ingredients slowly.
Pour in milk and mix gently.
Pour half the batter into your pan.
Add half the apple mixture on top.
Pour remaining batter over apples.
Top with rest of apple mixture.
Swirl gently with a knife.
Bake for 50-60 minutes.
Check with a toothpick in the center.
It should come out clean.
Let cool for 15 minutes.
Mix powdered sugar with milk.
Drizzle over cooled bread.
Let it set before slicing.