Ingredients
Equipment
Method
Prep and preheat
- Preheat the oven to 350F and grease a 9x5 loaf pan. Make sure the pan is fully coated so the loaf releases cleanly.
Make the batter
- Whisk the flour, baking soda, baking powder, cinnamon, and salt in a large bowl until evenly combined. The dry mix should look uniformly speckled.
- Beat the eggs, granulated sugar, vegetable oil, sour cream, and vanilla extract in a separate bowl until smooth. Stop once the mixture is glossy and free of streaks.
- Stir the wet ingredients into the dry ingredients until just combined, then fold in the diced peaches. Stop mixing as soon as no dry flour pockets remain to keep the crumb tender.
Add swirl and bake
- Pour half the batter into the loaf pan, then sprinkle the brown sugar and cinnamon mixture over it. Aim for an even layer so the swirl is visible from slice to slice.
- Top with the remaining batter. Gently level the surface so the center swirl stays dramatic.
- Swirl the top gently with a knife two or three times. You should see a ribbon forming in the center line.
- Bake for 60-65 minutes at 350F until a toothpick comes out clean. Look for a golden loaf with a crackled, caramelized cinnamon-sugar top, then cool 15 minutes before slicing.
Notes
Pro tip: dice the peaches fairly small and let any extra juice drain briefly so the loaf stays moist without turning gummy. Store tightly wrapped in the refrigerator up to 4 days; warm slices briefly for best texture. Freeze the fully cooled loaf (or individual slices) up to 2 months; thaw overnight in the fridge. If you want a lighter option, swap sour cream for plain Greek yogurt 1:1 to keep the loaf tender.