Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Prepare a 9×5-inch loaf pan by greasing and flouring it or lining it with parchment paper for easy release.
Prepare the Dry Ingredients: In a medium mixing bowl, combine the all-purpose flour, baking soda, baking powder, ground cinnamon, and salt. Use a whisk to blend them thoroughly, then set the bowl aside.
Cream the Butter and Sugar: In a large mixing bowl, use an electric mixer to cream the softened butter and granulated sugar together. Beat until the mixture is light and fluffy, which should take about 3-4 minutes.
Incorporate Eggs and Vanilla: Add the eggs to the creamed mixture, one at a time, mixing well after each addition. Stir in the vanilla extract until fully incorporated.
Combine Wet and Dry Ingredients: Gradually add the dry ingredient mixture to the creamed butter and sugar, alternating with the buttermilk. Start and finish with the dry ingredients, mixing gently until just combined. Take care not to overmix to ensure a tender loaf.
Fold in Apples: Carefully fold the diced apples into the batter, ensuring they are evenly distributed throughout without overworking the mixture.
Prepare the Cinnamon Swirl Mixture: In a small bowl, mix the packed brown sugar, ground cinnamon, and melted butter until a smooth paste forms.
Layer the Batter: Pour half of the apple batter into the prepared loaf pan, spreading it evenly. Spoon half of the cinnamon swirl mixture over the batter, then use a knife to gently swirl it through the batter. Pour the remaining apple batter on top, followed by the rest of the cinnamon swirl mixture, swirling again for a beautiful marbled effect.
Bake the Loaf: Place the loaf in the preheated oven and bake for 55-65 minutes. To check for doneness, insert a toothpick into the center; it should come out clean. If the top starts to brown too quickly, loosely tent it with aluminum foil.
Cool the Loaf: Remove the loaf from the oven and allow it to cool in the pan for about 10 minutes. Transfer it to a wire rack to cool completely.
Prepare the Glaze (Optional): If using, whisk together the powdered sugar, milk, and vanilla extract in a small bowl until smooth and free of lumps.
Serve and Enjoy: Once cooled, slice the loaf and drizzle with the glaze, if desired. Enjoy a delightful piece of apple cinnamon goodness!
Prep Time, Total Time, Servings: 20 minutes | 1 hour 15 minutes | 10 slices
– Presentation Tips: For an extra touch, serve slices on a wooden cutting board, garnished with a sprinkle of ground cinnamon and a few apple slices for decoration.
