Take whole milk in a deep pan at medium high heat, add 6 tbsp sugar. Boil it carefully without spilling for about 10 minutes.
Add lemon juice and stir. The milk gradually will curdle because of lemon juice. Let it slowly separate like paneer. Let it boil.
On another side of stove on medium high heat caramelize sugar. Add 2 tbsp sugar in a little pan/pot with few drops of water 4-5 droplets. Let it caramelize, without stirring. Do not be tempted to turn on high heat. It will happen. Do not leave it unattended.
Once you get deep amber color, add that caramel (caramelized sugar into milk mixture).
It will create bubbles and boil over, so be careful when you pour the caramel.
Stir and let the milk mixture cook until all the water evaporates from this mixture. It will easily take 30 minutes to 40 minutes for all the water to evaporate.
Make sure there is no water, natural fats will visibly separate out. At this point, stir or else the mixture will stick to the pan. Add cardamom powder and milk powder and mix everything well.
Once its cooked, turn off the heat and immediately transfer mixture into a prepared dish/try lined with parchment paper. Parchment paper will help lift it easily.
Let it cool off completely at room temperature and then place it in the fridge for few hours, it will give you cleaner squares.
If you plan on making round peda shape, then remove the mixture in a container and once it slightly cool scoop out rounds and shape them I round shape and slightly flatten it.
And, if you do not want to shape it either ways, just serve it as it is in a bowl.