Preheat oven to 350 degrees. Spray 8"x4" loaf pan with baking spray and set aside.
In a large bowl, whisk together flour, baking powder and salt.
In a medium bowl, add the sugar, oil, buttermilk, eggs, zest, juice and vanilla and whisk to combine.
Add buttermilk mixture to flour mixture and whisk to combine. Pour into prepared loaf pan.
Bake for 65 to 75 minutes, or until a toothpick inserted into the center comes out clean. Let cool in pan for 15 minutes and then transfer to a wire rack to cool completely.
To prepare glaze, in a small bowl, whisk the powdered sugar, lemon juice and buttermilk until well-blended. Drizzle over cooled cake, as desired.
Recipe by Alida's Kitchen at https://www.alidaskitchen.com/2013/01/31/lemon-buttermilk-cake/