Preheat oven to 170 deg C. Lined (9 x 5 x 3 by inch) loaf pan all sides up.

Sift together the flour, baking soda, cinnamon powder and salt into a bowl, set aside for later use.

Beat together eggs and brown sugar in a bowl of electric mixer at medium-high speed until very thick and pale and mixture forms a ribbon when beater is lifted, about 8-10 minutes.

Reduce speed to low and add oil in a slow stream, mixing, then mix in bananas, lemon juice and vanilla, remove from mixer. Combine flours and walnuts together and mixture gently and thoroughly with a rubber spatula. Lastly add in milk and mix well.

Pour the batter into the loaf pan, spreading evenly. Slice banana into half and place on top of batter.

Bake in preheated oven until golden and a skewer comes out clean for about 55-60 minutes.

Brush some melted butter on top of cake once it is out of the oven. Leave cake to cool on wire rack and dust with some snow powder before serving.