Chocolate banana and Macadamia Muffins

First of all - apologies as my muffins have no macadamias.  Thought there was some in the cupboard and was horribly mistaken!

2 cups self raising flour
1/3 cup plain flour
1/2 teaspoon baking soda
1 cup brown sugar
1 cup buttermilk
1 cup mashed banana
2 eggs, lightly beaten
1/3 cup vegetable oil
1 cup macadamias, chopped
1/2 cup grated chocolate

1. Preheat oven to 180 degree celcius.  Line a 12 hole  muffin pan with paper and patty cases (I got 18 muffins out of this recipe so you might want to do more).

2. Sift flours and soda into a large bowl.  Stir in sugar.

3.  In a large jug, whisk together buttermilk, banana, egg and oil.  Fold into dry ingredients with macadamias and chocolate.  Do not overmix.

4. Spoon mixture into cases until each one is 2/3 full.  Bake for 20-25 minutes until cooked when tested with a skewer.