Pre-heat oven to 350 degrees Fahrenheit / 175 Celsius.
Line a baking tin with parchment paper.
Rub the margarine through the flour until the mixture resembles breadcrumbs.
Add the dry ingredients – dried fruit, sugar, cocoa, and spices.
Mix the above together with the lemon zest. (If using lemon juice add this with the liquids in step 6.)
Mix together the milk and vinegar, then add the baking soda to the mix.
Pour into the dry ingredients and mix well.
Place the mixture into the tin and place in the oven, checking after an hour by inserting a skewer. If it comes out clean, the cake is done.
After removing from the oven, leave the cake to cool for around 10 minutes in the baking tin before turning out onto a cooling rack.
