Preheat your oven to 160 degrees C (fan) or 180 degrees C (conventional). Grease a 1 kg loaf tin and line with non-stick baking paper.
Place the eggs, caster sugar, soft butter or baking spread, self-raising flour, baking powder, milk, lemon zest, and lemon juice into a large bowl.
Beat everything together with an electric hand mixer for about 1 minute until smooth, pale, and well combined. Do not overmix.
Pour the batter into the prepared loaf tin and level the top with a spatula.
Bake for 35 to 40 minutes or until a skewer inserted in the centre comes out clean and the top is a gorgeous golden brown.
Allow the cake to cool in the tin for 10 minutes, then transfer to a wire rack to cool completely.
To make the set glaze, sift the icing sugar into a bowl and add lemon juice one tablespoon at a time, mixing until you get a thick but spreadable consistency. It should be white and opaque.
Spread the set glaze evenly over the top of the completely cooled loaf cake, letting it drip slightly down the sides.
Allow the glaze to set for 15 to 20 minutes before slicing and serving.