Preheat oven to 180 degrees. Grease and flour two 9 inch pans generously.
In a bowl, whisk the yogurt and sugar till melted. Add in the baking powder and baking soda, fold in and leave the mixture undisturbed for five minutes. The mixture will start to froth.
Add the oil and whisk.
In another bowl, whisk the flour, salt and cardamom together.
Pour the wet mixture and gently fold just till moist. Do not overfold, or the cake will get hard.
Pour equally into both pans and bake for 30 minutes or till the skewer comes out clean.
Allow to cool in the pan for five minutes. Flip onto a cooling rack and allow the cakes to cool completely.
For making the milk, heat the milk slightly with the saffron till it dilutes. Allow to cool. Whisk in all the ingredients and store in the fridge till use.
For the whipping cream, heat the milk in the microwave for 20 seconds and crush the saffron in. Allow it to dilute.
Whip the cream along with the sugar till stiff peaks. Fold in the saffron milk and refrigerate till use.
Keep the drained rasgullas and the crushed nuts ready.
For assembling, on a turn table, place one cooled cake. Poke it slightly with a fork all over. Spoon some milk all over it till wet.
Slather a thick layer of whipping cream over it. Cut some rasgullas into half and press down onto the cream randomly. Sprinkle half of the nut over.
Poke the other cake and slather some milk over it. Carefully place it on top of the prepared layer.
Cover with whipping cream all over the cake in a thin layer.
Allow the cake to rest in the fridge for 30 minutes just to set.
Now, slather the remaining whipping cream all over the cake in a uniform manner. Top with more rasgullas and the remaining nuts. You can stick some of the nuts to the sides as well.
Allow the cake to set for another two hours, before serving.
To serve, slice the cake, put into the plate, drizzle some of the milk over it. Dig in and enjoy!