Soak 6 - 7 pistachios in 1/2 cup of water for 20 minutes. Then peel and slice them. Keep it aside.
Grind rava and whole wheat flour in a mixer and take out in a bowl. Keep it aside.

Wet ingredients: In a grinder add curd, oil, boiled beetroot*, powdered sugar, roohafza, and gulkhand with a pinch of salt. Grind them until smooth.
Now add rava whole wheat flour mixture into wet ingredients and grind them as well.

Now take out the prepared cake batter in a bowl and keep aside for 30 minutes (covered).
After 30 minutes (add 2 tbsp of curd if the mixture looks dry) add baking soda or Eno, baking powder and mix it well.

Put batter into a greased baking pan and sprinkle topping over cake and with help of spatula press topping gently. Tab the pan.
Bake in the cooker for 60 minutes.

Tips:

Adjust sugar according to your taste.
Baking time may vary.
If cake batter looks dry, add 2- 4 tbsp of curd.
If baking in Oven: Bake in the preheated oven at 180 deg Celsius or around 360 Fahrenheit for about 1 hour. The baking time may vary. So keep checking the cake after 40 to 45 minutes.
For Boiled Beetroot: Boil medium size beetroot in a pressure cooker and then peel the boiled beetroot. Cut boiled beetroot into small cubes.

Pressure Cooker Method:
Grease the baking tin with oil and dust it by sprinkling whole wheat flour over greased surface evenly. Pour the mixture into the greased baking tin.

Important Notes:

Use the baking tin of 6 inches in diameter, so that it can easily get into the pressure cooker.
Use a 5-liter pressure cooker. It should be big enough to hold the baking pan.
Baking Tin should be made of Aluminium.

If baking tin comes into direct contact with the base of the pressure cooker, it can burn (overbake) the cake. So use pressure cooker container which has big holes in it or any aluminum small stand.
No gasket and whistle are needed. Remove them before baking.
Don’t add water to the pressure cooker.

How to Bake In A Pressure Cooker?

Heat the pressure cooker on high heat for 2 minutes. Use sea salt or sand as a layer inside a cooker. Put a steel stand on a layer of salt or sand.
Now put the cake tin containing the cake batter (Do not put water inside the pressure cooker).

Close the pressure cooker lid and do not put the whistle on the lid. Remove the gasket (rubber ring) from the lid.
Lower the flame after 2 minutes. Let it bake for 50 -60 minutes on low flame. After 60 minutes check cake with a knife, if the mixture does not stick, it means the cake is done.

If batter still sticks to knife then again bake for another 10 minutes. Do not open the lid immediately.
Eggless Pressure Cooker Cake is ready.