Preheat your oven to 350°F (175°C). Grease a 9×5-inch loaf pan and set aside.
Prepare Cinnamon Swirl:
In a small bowl, mix light brown sugar with 1 teaspoon cinnamon. Set aside.
Cream Butter and Sugar:
In a large bowl, beat softened butter, white sugar, eggs, and vanilla extract until light and fluffy.
Combine Dry Ingredients:
In a separate bowl, whisk together flour and baking powder. Gradually fold into the butter mixture until just combined.
Add Apples (Optional):
Gently fold in diced apples and nuts if using.
Layer the Batter:
Pour half of the batter into the prepared loaf pan. Sprinkle half of the cinnamon-sugar mixture over the batter. Add the remaining batter on top, then sprinkle the rest of the cinnamon-sugar swirl. Use a knife to gently swirl the cinnamon mixture through the batter for a marbled effect.
Bake:
Bake for 50–60 minutes or until a toothpick inserted in the center comes out clean. Let the loaf cool in the pan for 10 minutes before transferring to a wire rack to cool completely.
Serving and Storage Tips
