Preheat your oven to 180°C (350°F). Grease your loaf or bundt pan and set aside. In a large bowl, beat the softened butter and caster sugar together until the mixture turns pale and fluffy, about 3-4 minutes, and you hear a gentle squeaking sound.
Add the eggs one at a time, beating well after each addition. The mixture may look a bit curdled—that's okay. Stir in the lemon zest and lemon juice, which will brighten the batter and add a lovely citrus aroma.
Gently fold in the sifted flour and baking powder using a spatula, mixing just until the batter looks smooth and combined. Be careful not to overmix, as this keeps the cake tender.
Pour the batter into your prepared pan, smoothing the surface with the spatula. Tap the pan lightly on the counter to help release any air bubbles that might have formed during mixing.
Bake in the preheated oven for about 45-50 minutes. Check for doneness by inserting a skewer into the center; it should come out clean, and the cake should be golden brown around the edges.
While the cake is baking, prepare your glaze by mixing the icing sugar with 2-3 tablespoons of lemon juice until smooth. The consistency should be pourable but not too runny.
Once baked, remove the cake from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack and poke several holes all over the warm cake with a skewer.
Slowly pour the lemon glaze over the warm cake, allowing it to seep into the holes and coat the surface. The glaze will set as the cake cools, creating a shiny, crackly top.
Let the cake cool completely to allow the glaze to set fully. Slice and enjoy the moist, tender crumb with that bright, zingy lemon crust in every bite.
