Preheat oven to 325°F (165°C) and grease a bundt or loaf pan.
In a large bowl, rub lemon zest into sugar until fragrant.
Cream butter with lemon sugar until light and fluffy.
Add eggs one at a time, mixing well after each addition.
Mix in vanilla extract.
In a separate bowl, whisk flour, baking soda, and salt.
In another bowl, mix buttermilk, sour cream, and lemon juice.
Alternate adding dry and wet ingredients into batter, beginning and ending with dry ingredients.
Mix until just combined.
Pour batter into prepared pan.
Bake for 60–70 minutes until a toothpick comes out clean.
Cool before removing from pan and serving.
Combine the confectioner sugar with the lemon juice until smooth. Add to cooled cake and enjoy!