Preheat the oven at 180 C or 350 F.
Grease an 8 inch round or square pan with oil and set aside. I used 2 nos of 4.5 inch aluminium take away containers and did not grease it.
In a mixing bowl, whisk together ragi flour, cocoa powder, baking soda, salt together and set aside.
In a mixer jar, add bananas, milk, brown sugar and blend till smooth.
In a mixing bowl, add blended puree, coconut oil, vanilla extract and whisk well using a balloon whisk.
Add the dry flour mixture little by little and using a spatula mix gently till well incorporated.
Add walnuts, dark chocolate and once again mix gently.
Transfer to the greased pan. Sprinkle white chocolate chips on top evenly.
Bake for 35 to 40 mins or till a skewer inserted comes out clean. Timings will vary for each oven.
Take the pan out of the oven and let it cool down a bit.
Remove the cake out of the pan and transfer to a cooling rack to cool down completely.
Serve this eggless ragi chocolate cake slices with coffee or tea.