Soak the cashews in warm water for about 1-2 hours to soften them. Drain and rinse.
In a food processor, blend the soaked cashews until they form a fine powder. Be careful not to over-process, or it will turn into a paste.
In a non-stick pan, combine the cashew powder and chopped dates. Add a little water to help it bind. Cook on low heat, stirring continuously until it forms a dough-like consistency (about 5-7 minutes).
Stir in the cardamom powder and mix well. Remove from heat.
Grease a flat surface or a rolling pin with ghee. Transfer the mixture onto the surface and roll it out to your desired thickness (about 1/4 inch). Use a knife to cut it into diamond-shaped pieces.
Let the Kaju Katli cool completely before serving. Optionally, garnish with chopped nuts.
Store in an airtight container and enjoy your sugar-free Kaju Katli during Diwali!