Saute the apples, 30g of butter and brown sugar in a saucepan on low heat for 15 minutes, or until the sugar turns to a toffee consistency.
Blend until smooth and allow to cool.
Preheat the oven to 180°C.
Cream together the remaining butter and caster sugar until light and fluffy.
Add the eggs one by one, mixing well after each addition.
Splash in the vanilla extract and Frangelico and stir to combine.
Add the apple puree and sour cream. Combine the flour, baking powder, raisins and spices in a separate bowl, then fold into the creamed mixture.
Plase the mixture into a well-greased 23cm cake tin and bake until a skewer inserted comes out clean, about 1 hour.
Cool the cake completely before turning out.
To make the icing:
Cream the margarine adding the icing sugar while beating. Splash in the Frangelico and vanilla extract.
Add the milk a teaspoonful at a time until a spreading consistency is reached. Decorate as desired.