In a bowl, add all the dry ingredients – whole wheat flour, cocoa powder, baking powder, baking soda and salt. Mix the dry ingredients together well. Set aside.
In another bowl, add mashed bananas, sugar and mix well until the sugar is well dissolved. Add the oil and vanilla essence.
Whisk well until the oil is fully incorporated and the mixture is thick. Now add the milk/water and whisk it well.
Add the wet mixture to the dry mixture along with sunflower seeds. Gently the batter well without any lumps.
Add this batter to the lined baking tray (I used loaf pan) and even out the batter. Sprinkle chocolate chips on top and bake at 180°C for ~35 mins.
When a toothpick inserted comes out clean, remove the baking tray from oven. Let it cool down for 5 mins before turning it over. Once cooled down, slice as needed.
Store in an airtight container and stock it up in the fridge for over a week. The cake retains its moistness but if it seems a little dense, warm it in microwave for 30 secs. Serve cold or warm.