To make the cake:

Cup of Yum
1. Preheat the oven to 325°F (160°C). Spray a 9×5-inch (23 x 12 cm) loaf pan with nonstick cooking spray that contains flour. In a medium bowl, sift together the flour, baking powder, and salt. In a small measuring cup, whisk together the sour cream and lemon juice.
2. In the bowl of a stand mixer fitted with the paddle attachment, combine the lemon zest and sugar. Rub them together with your fingertips until the sugar is moist and fragrant. Add the butter to the bowl and beat the butter-sugar mixture on medium speed until very pale and fluffy, about 3-4 minutes. Scrape down the sides of the bowl as needed.
3. Mix in the eggs in three additions, beating well after each addition until the mixture is smooth (stop to scrape down the sides of the bowl as necessary). With the mixer on low, alternately add the dry ingredients in three additions and the sour cream mixture in two additions, starting and ending with the dry ingredients
4. Once all the ingredients have been added, scrape down the bowl and beat on low for another 30 seconds to fully combine. Use a rubber spatula to ensure that the batter at the very bottom of the bowl is uniform.
5. Transfer the batter to the prepared pan and smooth the top. Tap the pan on your work surface to release any air bubbles. Bake the cake for 55–65 minutes, or until a thin knife inserted near the center comes out with just a few moist crumbs. Transfer the pan to a wire rack and let the cake cool for 10 minutes before turning it out.
6. While the cake is baking, prepare the syrup. In a small saucepan, combine the sugar and lemon juice and set over medium-high heat. Cook, stirring frequently, until the sugar dissolves. Bring the mixture to a simmer and allow it to simmer for 2 minutes, then remove from heat and set aside.
7. Once you’ve turned the cake out of the pan (it should still be warm), brush the top and sides with the lemon syrup. It may seem like a lot, but use all of the syrup. Allow the cake to cool completely, about 2 hours.

To make the glaze:

1. Combine the confectioners' sugar and lemon juice in a small bowl, stirring until smooth. Pour the glaze over the top of the cake, ensuring it covers completely. Allow the glaze to set for at least 15 minutes before serving.