Preheat the oven to 180C. Grease and line a 2lb loaf tin.
In a bowl whisk together the quark, oil and eggs. Once smooth add the lemon zest and caster sugar and whisk again.
Fold in the flour. Once the batter is smooth pour into the loaf tin and bake for 40-45 minutes, or until a knife comes out of the centre clean.
Five minutes before the cake is cooked start the syrup. Bring the lemon juice and sugar to the boil, cooking until the sugar has fully dissolved. This will only take a minute or so.
Remove the cake from the oven and using a thin skewer created small holes over the top of the loaf. Pour the hot syrup on top and allow to cool down fully and soak into the sponge.
Once cool remove from the tin. Make the icing by mixing the icing sugar with a few splashes of milk. It should be fairly thick but also pourable.
Spread over the top of the cooled cake and allow to drip down the sides. Leave the icing to set fully before slicing and serving with a hot cup of tea.