Preheat your oven to 350°F. Grease a standard loaf pan thoroughly to prevent sticking, or line it with parchment paper for easy removal after baking.

In a large mixing bowl, combine sugar, eggs, sour cream, lemon zest, lemon juice, vanilla extract, and canola oil. Whisk until smooth and well incorporated. The zest will release aromatic oils, giving the batter a fragrant citrus aroma.

In a separate bowl, sift together the flour, baking powder, and salt. This step helps evenly distribute the leavening agents and prevents lumps in the batter.

Slowly add the dry mixture to the wet ingredients, stirring gently until just combined. Avoid overmixing, as this can lead to a denser loaf.

In a small bowl, mix the softened cream cheese with the powdered sugar until smooth and creamy. This sweetened filling will create the signature swirl in the bread.

Pour half of the lemon batter into the prepared loaf pan. Spoon about half of the cream cheese mixture over the batter in small dollops, then use a butter knife to gently swirl it into the batter without fully mixing it in. Repeat with the remaining batter and cream cheese mixture, creating another swirl layer.

Place the pan in the preheated oven and bake for 65–70 minutes. To prevent over-browning, loosely cover the top with foil during the last 20–30 minutes of baking. The bread is done when a toothpick inserted into the center comes out mostly clean, with only a few moist crumbs.

Allow the bread to cool completely in the pan before slicing. This is especially important for cream cheese-filled breads, as the filling needs time to set for clean slices.