- Adjust oven rack to middle position and heat oven to 355 F. Grease and flour 13 x 9”, or 8×8” baking pan.
- Combine flour, baking powder, baking soda, and salt in medium bowl.
- Combine buttermilk, lemon juice, and vanilla a separate measuring cup or bowl.
- With electric mixer on medium speed, beat granulated sugar and lemon zest until moist and fragrant, about 1 minute.
- Add butter to remaining sugar mixture and beat until light and fluffy, about 2 minutes. Beat in eggs, one at a time, until incorporated. Reduce speed to low. Add flour mixture in 3 additions, alternating with 2 additions of buttermilk mixture, and mix until smooth, about 30 seconds. Scrape batter into prepared pan and smooth top.
- Bake until cake is golden brown, and toothpick inserted into center comes out clean, 50-60 minutes.
- Let it rest outside the oven for about 10 minutes and then poke it with a knife. Drizzle all the glaze over the cake until it is all absorbed. Transfer cake to wire rack and let cool.