Heat 2 tbsp butter. Add whole spices: black cardamom, green cardamom, cinnamon, and cumin seeds. Sauté for 1 minute.
Add onions and tomatoes, cook till soft. Add turmeric, cumin, chili, coriander powders, salt, and cashews. Sauté 2–3 minutes.
Add 1/2 cup water and simmer for 10–12 minutes. Let it cool slightly, then blend the gravy into a smooth paste. Set aside.
In a bowl, combine mashed potatoes, grated paneer, chopped cashews, raisins, green chili, coriander, cornflour, and salt to prepare the dough for kofta. Mix into a soft dough.
Make small balls from the dough.
Deep fry in medium-hot oil until golden and crisp. Drain on a paper towel.
Reheat blended gravy in a clean pan. Add cream and garam masala. Simmer for 2–3 minutes till rich and creamy.
Arrange fried koftas in a serving dish.
Pour hot gravy over the top.
Garnish with cream and coriander. Serve malai kofta hot with naan, jeera rice, or roti.