Sweet Potato Muffins

These are a bit like carrot cake, a bit like passion cake. The frosting turned out a bit runnier than desired, but firmed up in the fridge overnight. I have another recipe which uses wholemeal flour and natural yogurt, but this just uses my standard  cake recipe as a base, so is ultra-quick and easy. 

Makes 12 standard-sized muffins (not the smaller fairy cakes)
400g self raising flour
4 tsps baking powder
200g sugar/ 200ml agave nectar
400ml milk
150ml coconut or rice bran oil/ melted butter
150g grated sweet potato
50g chopped walnuts
50g sultanas
2-3 tsps ground green cardamom (aka elaichi)
Frosting:
200g full-fat cream cheese
a few drop natural orange essence
3 tabs cooled melted butter
4 tabs icing sugar
orange/ lemon zest/ chopped nuts to decorate

• Combine the wet and dry cake ingredients in separate bowls, then add the wet to the dry and beat for about a minute. The grated sweet potato counts as wet, and the dried fruit, nuts and cardamom as dry. If using agave as sugar, then that counts as wet.
• Spoon into prepared muffin moulds/ tins (you may want to use paper cases) as quickly as possible and bake in an oven preheated to 180C for about 20 minutes, until springy to the touch. you can use a thin skewer to test if you want. The skewer will emerge with no mixture ion it when the cakes are done.
• Meanwhile, beat all frosting ingredients together and chill.
• Top each muffin, when cool, with a blob or swirl of frosting and decorate with peel and/ nuts.