Preheat your oven to 180 degrees Celsius. Prepare your loaf pan by greasing it with either oil or butter. You can use either an 8x4 inch or a 9x5 inch pan.
Begin by making the wet batter. Cream together the butter and sugar until soft and slightly creamy. Then, add the eggs one by one, whisking until the batter becomes smooth and creamy. Optionally, incorporate the lemon juice and vanilla extract.
In a separate bowl, combine the flour, lemon zest, and baking soda. Set this mixture aside.
Gradually add the flour mixture into the wet batter, stirring until the batter becomes thick. To adjust the consistency, pour in 1/3 cup of milk.
Transfer the cake batter into the prepared loaf pan and bake it in the preheated oven until fully cooked.
As the loaf cools, get the icing ready. Mix the icing sugar and lemon juice until you reach a thick consistency. If necessary, include more lemon juice until you achieve the desired thickness. Heat in the microwave for 10-15 seconds to create a lovely white glaze, and mix well
Once the loaf has cooled completely, drizzle the icing over the top, and garnish with extra lemon zest if desired.
Slice, serve, and enjoy!