01 -
Position the oven rack to the lower third and preheat to 177°C. Grease an 8×20 cm loaf pan with nonstick spray, or use a 9×23 cm loaf pan for a shorter loaf.
02 -
In a large bowl, whisk together the flour, baking powder, and salt. Set aside.
03 -
Using a handheld or stand mixer fitted with a paddle or whisk, beat softened butter on high speed until smooth and creamy, about 1 minute. Add granulated sugar and continue to beat on high speed for 2 minutes, until fully creamed. Scrape the bowl as needed.
04 -
With the mixer on low speed, add eggs one at a time, ensuring each is thoroughly combined. Stop the mixer after the last egg. Add sour cream, lemon juice, lemon zest, and vanilla extract, then beat on medium speed until just combined. Scrape bowl if needed; mixture may appear curdled, which is normal.
05 -
With mixer on low speed, gradually add the whisked dry ingredients, mixing just until incorporated. Use a whisk by hand to break up any large lumps if necessary. Do not overmix, as the batter will be very thick.
06 -
Spoon batter evenly into the prepared loaf pan. Bake for 55–65 minutes if using an 8×20 cm pan or 45–60 minutes if using a 9×23 cm pan. Tent with aluminum foil halfway through baking to prevent over-browning. Cake is done when a toothpick inserted in the center comes out mostly clean with a few moist crumbs.
07 -
Transfer baked cake to a wire rack and cool in the pan for 1 hour. Remove the cake from the pan and allow it to finish cooling completely on the rack or a serving plate.
08 -
Whisk confectioners’ sugar, lemon juice, and heavy cream or milk together until smooth. Drizzle or pour icing over the slightly warm or fully cooled cake. Serve immediately or after the icing has set.
09 -
Store leftover cake covered at room temperature for up to 3 days, or in the refrigerator for up to 1 week.