Scoop out the flesh from the mangoes. Place it in a food processor and process to a smooth purée. Set aside.
Place milk powder and condensed milk in a pan over low heat. Cook, stirring, for about 5 minutes or until it gets a semi solid consistency. Add mango purée, ghee and ground cardamom. Cook, stirring, for about 5-10 minutes or until the mixture is very thick and starts to leave the sides of the pan.
Grease and line a slice pan or plastic container with baking paper. Make sure the paper is overhanging at the sides. Pour the mixture into the container. Using a spatula, smooth the top.
Place in the refrigerator for about an hour to set. Once set, remove the burfi from the container and cut into desired shape. Garnish with toasted almond flakes.