Pass khoya through a grater. Put into a thick pan and fry on a slow fire just for one minute. Add powdered sugar and stir properly. When thickened, take off the fire, add cardamom powder and yellow colour and keep aside to cool.
To prepare stuffing, grate khoya, pumpkin and the petha with a fine grater. Put on a slow fire in a heavy pan for just 1/2 a minute. Constantly mix coconut powder and take off the fire. Mix a few drops of red colour and allow the mixture to cool.
Make balls of the yellow mixture and the pink mixture. Flatten and shape into hearts and ovals. Sandwich the pink mixture between 2 yellow layers and press. Decorate with silver leaves and serve.