01 -  Preheat oven to 350°F (175°C). Grease and line a 9x5-inch loaf pan with parchment paper. 
 02 -  Combine diced apples with granulated sugar and cinnamon in a small bowl. Set aside. 
 03 -  Mix brown sugar and cinnamon in another bowl. Set aside for layering. 
 04 -  Cream softened butter and granulated sugar in a large mixing bowl until light and fluffy. Beat in eggs one at a time, followed by vanilla extract. 
 05 -  In a separate bowl, whisk together all-purpose flour, baking powder, and salt. Alternately add the dry mixture and milk to the creamed ingredients, starting and ending with the flour. Stir just until incorporated. 
 06 -  Spread half the batter in the prepared loaf pan. Top with half the apple mixture and sprinkle with half the cinnamon swirl mixture. Repeat layering with remaining batter, apples, and swirl. 
 07 -  Gently swirl layers together using a butter knife for a marbled effect. 
 08 -  Bake at 350°F (175°C) for 50-60 minutes, or until a toothpick inserted in the center comes out clean. 
 09 -  Cool loaf in pan for 15 minutes. Transfer to a cooling rack and allow to cool completely. 
 10 -  In a small saucepan over medium heat, melt granulated sugar until amber, swirling the pan occasionally. Add butter and stir until fully melted. Carefully whisk in heavy cream and remove from heat once bubbling subsides. Stir in flaky sea salt. Let glaze cool slightly before using. 
 11 -  Drizzle cooled loaf with salted caramel glaze prior to slicing and serving.