Preheat oven to 350℉. Grease and flour a 9x5 inch loaf pan.
Using an electric mixer, beat the butter and granulated sugar together until smooth. Add in the eggs, one at a time, beating until completely blended; then add the vanilla extract and mix until smooth.
Pour HALF the batter into the loaf pan. Add HALF the apples and then HALF the brown sugar mixture, covering the batter.
Pour remaining batter over apple/brown sugar layer. Top again with remaining apples, then brown sugar mixture. Lightly pat down apples slightly into the batter; then, using a knife tip, gently swirl brown sugar mixture through the apples.
Bake at 350℉ for approx. 30-40 minutes, or until a toothpick inserted into the middle of the loaf comes out clean. (oven temps. vary, so keep an eye on it from the 30-minute mark on).
Apple Cinnamon Bread https://www.thegratefulgirlcooks.com/apple-cinnamon-bread/