Make the sugar syrup: boil sugar and water with crushed cardamom until slightly sticky (about 5 minutes). Remove from heat and stir in rose water. Keep warm.
Make the dough: mix milk powder, flour, and baking powder. Rub in softened ghee until crumbly. Add milk one spoon at a time and knead gently into a soft, smooth dough. Do not over-knead.
Divide dough into 20-22 equal portions. Roll each gently between your palms into a smooth ball with no cracks. Cracks will cause breakage while frying.
Heat oil on low-medium heat. Test by dropping a tiny piece of dough — it should rise slowly. Fry the balls in batches on low heat, stirring gently, until deep golden brown — about 8-10 minutes.
Transfer hot jamuns directly into the warm sugar syrup. Let them soak for at least 1-2 hours. They will double in size. Serve warm, garnished with crushed pistachios.