Preheat oven to 180°C (conventional bake). Grease and line the base of a 13cm x 23cm x 70 (6 cup capacity) loaf tin with baking paper.
Sift flour, baking powder, baking soda and Gregg's Mixed Spiceinto a mixing bowl.
In a separate bowl beat together raw sugar, oil, egg and mashed bananas to combine. Pour into the dry ingredients along with the chopped feijoas. Fold into the dry ingredients to mix.
Pour into prepared loaf tin. Bake for 55 - 60 minutes until cooked. A skewer inserted into the middle of the loaf will come out clean. Leave in the tin to cool for 10 minutes before turning onto a cake rack to cool completely. Cut into slices to serve.