Preheat your oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan or line it with parchment paper for easy removal later.

In a medium bowl, whisk together the flour, lemon zest, baking powder, baking soda, and salt. Set aside.

In a large bowl, whisk the sugar and eggs until smooth and slightly thickened. Add the oil, buttermilk, lemon juice, and vanilla extract, mixing until combined.

Gradually fold the dry ingredients into the wet ingredients, mixing just until no flour streaks remain. Avoid overmixing to keep the bread tender.

In a separate bowl, beat the softened cream cheese, sugar, egg, and vanilla extract until smooth and well combined.

Pour half of the lemon batter into the prepared loaf pan. Spoon the cream cheese mixture over the lemon layer. Spread carefully, then pour the remaining lemon batter on top.

Using a knife, gently swirl the cream cheese layer through the batter to create a beautiful marbled pattern.

Bake for 50–60 minutes, or until a toothpick inserted into the center comes out clean (a few moist crumbs are okay). The top should be golden and slightly springy.

Let the bread cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.

For an extra citrus punch and beautiful sheen, mix powdered sugar with lemon juice until smooth and pourable. Drizzle over the cooled bread and garnish with lemon zest.