In a bowl combine dry milk, confectioners' sugar, and corn starch; mix well.
Add melted butter and mix; mixture will become crumbled. Add whipping cream; mix well.
Put ingredients in a sauté pan, preferably a non stick pan. Cook on low to medium heat (180 ºF). A thin layer of Malai (Clotted cream Devonshire) will form on the top surface, keep folding it in. In about ten minutes you should have a nice thick Rabri. If you want it thinner, add more whipping cream.
Stir in cardamom seeds, pistachio nuts and almonds; mix and remove from heat. Set aside to let the rabri cool down to room temperature.
After mixture has reached room temperature, transfer into a serving dish and refrigerate. Serve well chilled.