Instructions

1. Grease and line an 8 inch square cake tin with baking or parchment paper. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced.
2. In a large bowl, add plain flour, baking soda, baking powder and cinnamon.
3.  In a small bowl, peel and mash the bananas well. In a separate large mixing bowl, add butter and sugars and beat with an electric mixer for a a couple of minutes until pale and creamy. Add vanilla and eggs, one at a time, beating until combined.
4. Add dry ingredients to the butter mixture, along with buttermilk and the mashed banana. Gently fold with a spatula until just combined. Stir in walnuts. Transfer mixture to prepared pan and bake for approximately 30-35 minutes or until a skewer inserted comes out clean.
5. To make the cream cheese frosting, add butter and cream cheese to a large mixing bowl. Beat with an electric mixer for 2-3 minutes until smooth and creamy. Add vanilla. Add sugar, 1 cup at a time, and continue to beat until smooth.
6. Spread frosting on cake and use a small spatula to spread to the edges. Sprinkle over chopped walnuts.