Chai Swirl Cake
Slightly adapted from the recipe Ruby Tandoh wrote for The Guardian

Cake                                                            Swirl                                                                      Butter Icing

150 g margarine                                         6 cardamom pods, seeds only, ground               50g butter
150g sugar                                                   1 tsp fennel seeds, ground                                  150g icing sugar
3 large eggs                                                 2 tsp ground cinnamon                                      1 tbsp milk
2 tsp vanilla extract                                    1 tsp ground ginger                                             ground cinnamon
150g plain flour                                          1/4 tsp black pepper
2 tsp baking powder                                  25g soft light brown sugar
1/4 tsp salt

Oven 180C/350F/gas mark 4
Line a 2lb loaf tin

Make your cake using your preferred method (I do it as an all in one). Scoop less than a third of it into a separate bowl and mix in the spices and brown sugar. Dollop it into the tin and use a knife to swirl the two cake mixes together. Bake for 50 to 55 minutes until it is cooked. Leave to cool for a while before removing from tin. It bakes in less time if you use a round tin to cook it in.
Ice with butter icing and either flavour the icing with ground cinnamon or dust with cinnamon.