Thinly slice or grate the jaggery so it dissolves easily. Add it to a bowl with hot water and stir until the jaggery has completely dissolved.
Crush the saffron strands in a mortar and pestle and add them to the jaggery water. Let the jaggery water cool down completely.
Coarsely grind the fennel seeds in a mortar and pestle.
In a bowl, combine the whole wheat flour, crushed fennel seeds, cardamom, and kosher salt. Mix well.
Add the cooled jaggery water and mix well. Add 2 to 4 tablespoons of additional water to bring the batter to a pourable consistency. The amount you need will depend on how coarse your flour is.
Batter consistency depends on the coarseness of the wheat flour. Add water gradually until it pours easily but isn't watery.
Cover and let the batter rest for 30 minutes. Give it a quick stir once more before cooking.
Heat a medium-sized pan over medium heat. Drizzle in ½ teaspoon of ghee. Gently pour about 3 tablespoons of batter onto the pan to form a 3-to-4-inch malpua. Do not spread the batter with a spoon; it will spread on its own. Cook 2 to 4 malpuas at a time, depending on the size of your pan.
Cook for 2 to 3 minutes on medium heat. Drizzle a bit more ghee on top, then carefully flip once the bottom has turned golden brown. Cook for another 2 to 3 minutes.
Remove from the pan and repeat with the remaining batter.
Garnish with sliced pistachios and serve warm with a bowl of rabdi.
The malpuas are best served fresh off the pan. Reheat leftovers in a skillet for about a minute per side.