Take cashews in a clean dry mixer jar. Make cashews into a very fine powder. Measure 1 cup of cashew powder and set aside.
Take ½ cup sugar in a pan. Add ¼ cup water and mix well. Cook this sugar solution on medium heat and make a one string sugar syrup.
One the sting consistency is reached add the cardamom powder.
Add the cashew powder, cocoa powder and mix thoroughly. Cook this mixture for 3-4 minutes on medium flame. Switch off the flame once the mixture turns into a soft mass. It is fine even if you remove it a tad early but do not over cook. If over cooked the mixture will turn hard and brittle.
Once the mixture is warm, knead it very well. Knead well for 5-7 minutes.
Roll the cashew dough into a ¼" thick circle. Roll in between two butter papers for easy rolling.
Cut into square or diamonds of desired size. Serve chocolate kaju katli as needed.