Make sugar & water mixture: Combine the water and sugar in a saucepan or pot. Heat over medium-high heat until it reaches a boil. Once the water begins to boil, turn off the heat.
Heat a pan over medium-low heat. Add ghee & let it melt. Stir in the whole wheat flour. Cook, constantly stirring, until it begins to becomes golden.
It will take around 7-8 minutes to roast and get the desired golden brown color and aroma. Do not stop stirring, or else the aata will burn. Mix in the cardamom powder.
While stirring, pour in the water-sugar mixture. Be cautious since there will be some spatter when you first start pouring, but this will stop after the mixture is poured. Mix vigorously to prevent lumps from forming.
The halwa will thicken as it boils. Continue to stir for 1-2 minutes.
Remove from the heat. Do not overcook, as it can get lumpy.