Grease a 20cm/7 inch springform pan and preheat the oven to 180 Celsius (350 Fahrenheit).
Place the bananas in a food processor and process until smooth. Add the remaining cake ingredients and process to combine. Pour the batter into the springform pan and bake for 40 minutes to 1 hour. Check the cake after 30 minutes as you may need to cover it with foil to prevent burning before the cake is cooked through. Remove from the oven and let the cake cool completely in the tin before removing.
While the cake is cooling keep the oven on at 180 celsius (350 fahrenheit) and make the honey roasted pecans. Combine the pecans, honey, sea salt and boiling water in a bowl and mix to combine. Place on a tray lined with baking paper and bake for 15 minutes, stirring about half way through to make sure they are evenly cooked. Remove the tray from the oven and set aside to cool.
To make the frosting combine the butter and cream cheese in the bowl of an electric mixer fitted with a paddle attachment and beat until smooth and creamy. Add the icing sugar and cinnamon and beat for another 5 minutes, or until pale and fluffy.
Spread the frosting over the cooled cake and top with chopped roasted pecans.
Any left over pecans are wonderful with ice cream, in salads or simply on their own.Note amounts in ounces and pounds have been rounded. If you need to convert weights you will find a great converter here