Measure and Sieve the whole wheat flour and mix well with baking soda, baking powder, and salt. Also, preheat the oven to 180 degrees C for 10 minutes.
Measure and keep all the other ingredients ready. Take a ripe banana and cut them into slices.
Mash the bananas well with a fork. Alternatively, you can blend the chopped banana pieces in a blender to puree them. Once the bananas are well mashed, add sugar.
Then add oil followed by vanilla essence. Stir it well with a hand whisk until the sugar is completely dissolved. Mix well so that the oil is mixed evenly.
Once all the wet ingredients are mixed well, add the sieved whole wheat flour mixture to the wet ingredients.
Gently fold everything well for 10-15 seconds. Don't over mix. Then add crushed nuts to the mix and give a stir. The final mixture should be thick.
Grease a cake pan with oil. Pour the mixture into the cake tin and gently tape it. Bake in the preheated oven at 180 deg C for 35 -40 minutes (baking time depends on the size of the cake pan and oven) at 180° Celsius till a toothpick inserted in the center comes out clean. Allow cooling in the tray for 5 minutes once done. Once the cake is warm, cut into pieces and serve!