Preheat oven to 180°C Grease and line two 10 x 18cm loaf tins with baking paper. In a bowl, mix together the brown sugar and almonds and put aside.
In a large bowl, mix together the sour cream and bicarbonate of soda, set aside for 5 minutes then stir in the melted butter, sugar and eggs. In another bowl, combine the flour, baking powder and cinnamon. Gradually fold in the sour cream mixture, followed by the bananas.
Pour the mixture equally into the prepared tins and sprinkle the brown sugar mixture on top.
Bake for 1-11/2 hours or until a skewer comes out clean. Set aside and cool in tins for about 20 minutes before turning out onto a wire rack to cool completely.