Preheat your oven to 350°F (175°C). Grease a baking sheet.
In a mixing bowl, whisk together flour, sugar, baking soda, and salt.
In another bowl, combine buttermilk, melted butter, eggs, and lemon zest.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined.
Pour the batter into the prepared baking sheet and spread evenly.
Bake for 25 minutes or until a toothpick inserted into the center comes out clean.
While the cake is baking, prepare the glaze by mixing powdered sugar and lemon juice until smooth.
Once the cake is done, let it cool slightly before drizzling the glaze over the top.