Ingredients
Method
- Peel, core, and dice apples into small cubes (about 1/4 to 1/2 inch). Toss with 2 tbsp dark brown sugar and 1 tsp cinnamon until evenly coated. Set aside.
- In a small bowl, stir together 1/2 cup dark brown sugar and 2 tsp cinnamon until combined. Set aside.
- Preheat oven to 350°F (175°C). Line a standard 1-pound loaf pan with parchment paper on all sides, leaving an overhang on the long edges for easy removal.
- Beat softened butter and granulated sugar together on medium speed for 2 to 3 minutes until pale and fluffy. Scrape down the bowl. Add eggs one at a time, beating after each addition. Mix in vanilla extract.
- In a separate bowl, whisk together flour, baking powder, and salt. With the mixer on low, add half the flour mixture, then pour in the milk and sour cream, then add the remaining flour mixture. Mix only until no streaks of flour remain. Do not over-mix.
- Spread half the batter into the prepared loaf pan. Scatter half the cinnamon apples over the batter, then sprinkle with half the cinnamon sugar. Spoon remaining batter on top, spread gently, then top with remaining apples and cinnamon sugar.
- Bake on the center rack for 50 to 55 minutes, checking at 45 minutes. The loaf is done when the top is deep golden brown and a knife inserted in the center comes out clean. If the top browns too quickly, tent loosely with aluminum foil.
- While the loaf cools in the pan, whisk together powdered sugar, 1 tbsp milk, vanilla extract, and a pinch of salt until smooth. Adjust consistency with drops of milk or extra powdered sugar as needed.
- Cool the loaf in the pan for at least 20 minutes, then lift out using the parchment handles and transfer to a wire rack. Cool completely before drizzling with glaze.
Notes
Use room-temperature butter and eggs for best results – pull them from the fridge at least 30 minutes before starting. Spoon flour into the measuring cup and level off; do not scoop directly from the bag. Dark brown sugar gives the swirl a deeper, caramel-like flavor and is worth using over light brown sugar. Cool the loaf completely before glazing so the glaze sits on the surface instead of absorbing in. The apple mixture stays naturally moist inside even when fully baked – look for no wet batter on the knife, not dry crumbs.
