Preheat the oven to 180C fan/200C/400F/gas mark 6 and line an 8 hole mini loaf baking tin.
In a large bowl/bowl of a stand mixer, add all the cake ingredients and combine until smooth. If very stiff, add a little more milk. Pour into tin and bake 20-25 minutes, until golden and a skewer inserted comes out clean.
Let cool on a wire rack before making the glaze.
Make the glaze by combining milk and icing (confectioners) sugar. It should be spreadable but not too runny. Top with extra lemon zest, if using and let set before serving.