Step 1

Place 3 large eggs and 1 cup sour cream on the counter. Let sit at room temperature for at least 30 minutes.

Step 2

Arrange a rack in the middle of the oven and heat the oven to 350ºF. Line a 9x5-inch loaf pan with parchment paper so the paper hangs off the two long sides and coat with cooking spray.

Step 3

Place 1 1/2 cups all-purpose flour, 1/2 teaspoon baking powder, 1/2 teaspoon kosher salt, and 1/4 teaspoon baking soda in a medium bowl, and whisk to combine.

Step 4

Finely grate the zest from 2 medium lemons (about 2 tablespoons). Squeeze the lemons until you have 3 1/2 tablespoons juice. Place 1 cup granulated sugar and the lemon zest in a large bowl. Use your fingers to rub the zest into the sugar until it's well-combined and fragrant. Add the eggs, sour cream, 2 tablespoons of the lemon juice, 1/2 cup vegetable or canola oil, and 1 tablespoon lemon extract, and whisk until the sugar is dissolved and no lumps from the sour cream remain.

Step 5

Add the flour mixture and whisk until smooth, about 30 seconds. Transfer the batter to the prepared pan and smooth the top with a spatula.

Step 6

Bake until lightly browned and a toothpick inserted in the center comes out clean, 50 to 60 minutes. Let cool for 15 minutes in the pan. Lift the cake from the pan using the parchment paper, place on a wire rack, and let cool completely, about 1 hour.

Step 7

Whisk 1 cup powdered sugar and the remaining 1 1/2 tablespoons lemon juice together in a small bowl until smooth and creamy. Spread evenly over the top of the cake, letting some of it drip down the sides. Let sit until the icing is set, about 30 minutes.