Heat 1 litre full fat milk in a sauce pan.
When it comes to boil , stir well and add about 30 saffron strands.
Stir well and boil milk on low flame till it reduces to half . During the process , milk froths and comes up . Stir , scrape edges and continue to boil on low flame. It takes about 30 -35 minutes for milk to reduce , half of the volume.
Whilst in a small mixer jar / blender , add sugar , cashews and cardamom pods and make fine powder .
Add sugar powder into reduced milk, stir well and bring to 1 boil.
Turn off the stove, add chopped pistachios , slivered almonds and 1 teaspoon of dry crushed rose petals or few drops of rose water or kewra water. If you are using rose essence or kewra essence , then add 1 drop only.
Stir well everything and set aside.
While adding rasgulla into rabri milk syrup , make sure Rasgulla are warm. If rasgulla are refrigerated , heat rasgulla syrup , add rasgulla , let it become warm .
Then squeeze in extra sugar syrup from rasgulla , press and flatten rasgulla balls between fingers and add into hot/warm rabri.
Let rasgulla sit in rabri for about 45 to 60 minutes. Once it cools completely, transfer to a air tight container and chill in refrigerator. Rasmali stays good upto 1 week when refrigerated .
Serve chilled rasmali.