Prep: Preheat your oven to 350°F and grease the inside of one loaf pan. Set it aside.
Zest your lemon and set aside the 1 TBSP zest. Extract the juice from the lemon as well, you need ½ cup for the batter and 1 tablespoon for the icing.
Batter: In a large mixing bowl, stir together the baking powder, baking soda, salt, and flour. Make a well in the center of the dry mixed ingredients and set it aside.
In a separate small bowl, whisk together the eggs, lemon zest, and sugar until well blended. Set aside.
Using a third small bowl, whisk together the sour cream, olive oil, lemon juice, and milk.
Proceed to pour the sour cream mixture into the egg mixture and then whisk them together well.
After that, add the wet ingredients to the well you made in the dry ingredients, adding it all at once. Gently fold the dry and wet ingredients together until combined, be careful not over mix. Just enough to combine the ingredients together.
Pour the batter into the prepared loaf pan.
Bake: Bake in the preheated oven for 50-60 minutes or until a toothpick can be inserted and come out clean. Allow the loaf to cool for 15-20 minutes before turning the loaf out onto a cooling rack. Let cool completely before icing.
Lemon Icing: Prepare the icing by creaming together the butter, powdered sugar, lemon juice, and 1 tablespoon of milk until smooth and creamy. Add in additional milk, 1 tablespoon at a time, as needed, until you have reached your desired consistency.
Once the loaf has cooled, spread or drizzle the icing over the top. Enjoy!