There are two ways to make it. The first one has no milk, and has a longer shelf life.
Method 1: Using sugar syrup
What you need, makes about 20 burfis about 2 inches each.
2 cups whole cashews
1 cup sugar
1/2 cup water
1/4 cup ghee
A large ziploc bag or wax paper
Lightly toast the cashews in a glass bowl in the microwave for about 30 seconds. You may also pan roast them for 2 minutes.. Let them cool. Powder them to a grinder. Set aside.
Slit the ziploc bag on two sides, so it resembles a folder. Grease the insides of the plastic bag with ghee and set aside. You may use wax paper instead.
Ina non-stick pan, boil sugar and water together on medium heat. Once the sugar dissolves and the mixture comes to a rolling boil, take a few drops of the syrup and pour it into a cup of cold water. It is dissolves, it is not the right stage yet; keep boiling. When you pour the syrup in cold water, it should have a thread consistency, and form a soft ball when stirred.
Pour in the powdered cashews, and keep stirring, until it forms a thick dough consistency. This should take about 6 to 8 minutes on medium heat. Turn off the heat. When the dough cools from hot to lukewarm, it is ready to knead. Grease your hands generously with ghee. Knead the dough to a smooth texture. Form a ball without crumbs or cracks. Place it inside the greased ziploc. Roll it out gently with a rolling pan to about 1/4th or 1/2 inch. While the dough is warm, cut them into desired squares or diamonds. Let cool before storing in airtight containers. They will stay fresh for a week.
You can swap out cashews with almonds to make almond burfis. Enjoy!
Method 2: Using condensed milk
What you need, makes about 20 diamond burfis about 2 inches each.
3 cups whole cashew nuts
1 cup sweetened condensed milk
1/2 cup whole milk
1 Tbsp ghee
Pinch of cardamom powder
2 Tbsp milk powder or more
Powder the cashews in a blender. Once they are nearly fine, add milk and grind them to a smooth paste. Set aside.
Grease a plate or baking tray lightly with ghee and set aside. You may also use a wax paper to line the tray instead.
Place a pan on medium heat. Pour in cashew paste, condensed milk and cardamom powder. Cook on medium for about 10 to 12 minutes on medium heat until the liquid begins to come together to a dough consistency.
Add ghee and continue to knead the dough with a stirring spoon on medium heat. Once the dough is seen leaving the sides of the pan and resembles a soft knead-able dough, turn off the heat.
Add in milk powder and knead the dough until it is not sticky anymore and firm enough to roll out. Pour out the dough on the greased plate. or tray with wax paper.
Roll it out flat and let it set for about 30 minutes. Cut out horizontal strips, then cut them diagonally to form diamond shapes.
Serve or store in an air tight container. It will last a few days at room temperature. If you refrigerate it, the burfi will hold good for up to a few weeks. Enjoy.