Preheat oven to 350°C 170°C and line an 8 inch cake tin with parchment paper.
Melt the margarine (I just zap in the microwave)
Mix the flour, brown sugar and baking powder together. Add the spices and mix in the raisins and cranberries. Add in the Apple Cider Vinegar and mix.
Mix in the melted margarine and milk to the dry ingredients and mix until you've a nice smooth batter.
Pour into your prepared tin and bake for 25-30 minutes or until a toothpick comes out clean, or the cake has shrunk from the edged and bounces back when you tap the top.