1/2cupunsalted butter, softened to room temperature
1cupgranulated sugar
2largeeggs, at room temperature
3tablespoonslemon juice
1teaspoonvanilla extract
1/2cupbuttermilk
For the Lemon Icing
1 1/4cupspowdered sugar
2-3tablespoonslemon juice
Instructions
Preheat oven to 350 degrees F. Generously butter and flour a standard 9×5 loaf pan (making sure to get butter in all the corner grooves and discard any excess flour.)
In a large bowl, whisk together the flour, baking powder, lemon zest, and salt. Set aside.
In the bowl of a stand mixer (fitted with the paddle attachment) or using an electric mixer, cream together the butter and sugar on medium-high until light, fluffy, and pale in color, scraping down the sides of the bowl with a rubber spatula as necessary, about 4 minutes.
Reduce speed to low and with the mixer running, add eggs one at a time, allowing the first to fully incorporate before adding the next. Then beat in the lemon juice and vanilla extract. Scrape down the bowl again.
With the mixer on low, add about one-third of the flour mixture and mix until almost combined, then add half the buttermilk and mix until just combined. Repeat with another third of flour mixture and then the last half of the buttermilk, ending with the last third of the flour. Beat until just incorporated. Don’t over-mix.
Using a rubber spatula, give the batter a final turn to make sure there are no lumps at the bottom of the bowl. The batter will be a thick and very creamy.
Pour batter into the prepared loaf pan. Bang the pan on the counter once or twice to bring up any air bubbles. Bake for 45-55 minutes until the cake is golden brown and a toothpick comes out mostly clean from the center and the top feels firm to the touch. (If after about 30-40 minutes the top is browning too much, tent a piece of aluminum foil over top and continue baking. All ovens run differently, so baking times can vary. Keep an eye on it.)
Remove cake from the oven and allow to cool for 30 minutes inside the pan. Then invert from pan and transfer to a wire rack or serving dish to cool completely.
Once the cake is completely cooled, make the icing. Whisk together the powdered sugar and 2 tablespoons lemon juice. (Add more powdered sugar to make it thicker or more lemon juice to thin it out. The consistency should be thick, but pourable.) Pour over the top of the loaf making sure it covers the top completely. Allow the icing to set/dry completely before slicing.