Preheat oven to 350 degrees F. Grease a 9x5-inch loaf pan.
In a small bowl, mix together the brown sugar and cinnamon. Set aside.
Using an electric mixer, cream together the butter and sugar until it is light and fluffy.
Add in eggs and vanilla extract.
Mix in flour, baking powder, and milk until just combined.
Pour half of the batter into the prepared loaf pan. Top with half the apples. Sprinkle with half of the cinnamon-sugar mixture.
Pour the remaining batter into the loaf pan and spread to the edges. Top with the remaining apples. Sprinkle remaining cinnamon sugar on top.
Bake for 50-55 minutes until a toothpick inserted into the center comes out clean.
Allow the bread to cool completely before removing it from the pan.