Add semolina and sugar in a grinder jar.
Grind them to a fine powder.
Then add curd, milk and oil in the grinder jar. Make sure curd shouldn't be sour and both curd and milk should be at room temperature.
Transfer this batter in a bowl.
Add coffee powder, cocoa powder and salt.
Give them a good mix.
Leave the batter on rest for 30 minutes.
After 30 minutes, check the consistency of batter. If it has turned too thick, you can add bit of milk but we didn't need to add as the consistency was perfectly fine.
Add baking soda, baking powder and vinegar.
Mix well.
Then add chopped chocolate chunks.
Mix well.
Transfer the batter in greased cake tin.
Oven was preheated @170°C for 10 minutes with both the rods on but after putting the cake mould inside, turn the rod on lower mode only and bake for 30-35 minutes. Thereafter turn both the rods mode on and bake for 8-10 more minutes.
Check the cake by inserting a toothpick and if the toothpick comes out clean, it's a sign that cake is thoroughly baked.
When the cake cools down completely, demould it.
Cut into slices and enjoy.