you will need fresh chenna to make the sandesh. please refer to chenna recipe.
once the chenna is ready. then you just crumble it and blitz in a blender or grinder with cocoa powder and sugar, till the mixture becomes smooth.
add this mixture to a thick bottomed non stick pan or frying pan. with continuous stirring begin to cook on a low flame.
after a few minutes, the mixture will come to have a smooth and molten consistency.
continue to stir and cook. you will see in pic 4 above, that the color has darkened and the sandesh mixture has lost its moisture and has started coming together. the chenna should have some moistness and must not have a dense rubbery texture. also no oil or fat should be released from the sandesh mixture.
it will take about 5 to 6 minutes to get this texture on a low flame. the timing may vary depending on the intensity of the flame, the size and quality of the pan and the quality of chenna.
take all of the sandesh mixture on a small thali or plate. let it become warm or cool down completely. gently knead the mixture.
the kneaded sandesh mixture is shown in pic 6 above.
make small or medium sized balls from the sandesh. you can make designs on top by pressing with your thumb or with a fork or toothpick.
you can also garnish chocolate sandesh with blanched & sliced almonds or pistachios, raisins or cashews.
serve chocolate sandesh immediately. if not serving, then refrigerate and serve them later.