Preheat oven to 180°C, 400°F, Gas Mark 6
Using a fine grater, grate the rind off of a lemon and add to the cake mixture.
The lemon that you have taken the rind from, cut it in half and squeeze to get the juice from the lemon, be careful not to get any pips in the lemon juice.
Add the flour, sweetener, baking powder, low fat spread, eggs, lemon rind and lemong juice into a large bowl and mix until it is all combined.
Once the mixture is combined, pour the mixture into a lined loaf tin.
Put the lemon cake in the oven for 20 - 25 minutes, or until a skewer comes out clean when inserted into the middle of the loaf and it is golden in colour.