Piccolo Parsnip and Orange Cake with Mascarpone Frosting

Ingredients

250g self-raising flour
1 tsp baking powder
250g butter, softened
250g brown sugar
4 medium eggs
2 tsp mixed spice
300g Piccolo parsnips, washed, trimmed and grated
50g pecan nuts, chopped finely
1 tsp vanilla
1 tbsp maple syrup
Rind of 1 orange and 1 tbsp the juice
A little milk

Frosting:
250g mascarpone
250g cream cheese
1 tbsp maple syrup
Rind of 1 orange and a little juice

Pecan nut halves, to decorate
Icing sugar, to decorate