Pour the batter into the prepared loaf pan. Bake for 50-60 minutes or until a toothpick inserted into the center comes out clean. Let cool in the pan for about 5 minutes, then turn out onto a wire rack.
While the bread is cooling, whisk together powdered sugar, lemon juice, zest, and milk in a small bowl. Adjust the thickness by adding more powdered sugar or milk as needed.