Measure and keep all the ingredients ready. Take sugar and cardamom/Cardamom powder in a blender. Grind it to a smooth powder. Set aside.
Slice bananas. Puree the bananas in a blender without adding water. Keep aside.
Take 1 cup of semolina/Sooji in a mixing bowl. Add in powdered sugar to it.
Add baking powder to it. Mix well.
Then add oil/butter/ghee. Mix well so that the oil is mixed evenly.
Now add the banana puree to it. Gently mix everything well.
Finally, add chopped/powdered walnuts to it. Set this mixture aside for 10 minutes. In the meantime, preheat the oven to 180 degrees for 10 minutes and grease the loaf pan/cake tin with oil.
After 10 minutes, Pour the semolina banana mixture to the loaf pan. Bake in the preheated oven for 20-25 minutes (baking time depends on the size of the loaf pan and oven) at 180° till a toothpick inserted in the center comes out clean. Allow to cool in the tray for 5 minutes and cut the cake when it's completely cooled down.