Bring khoya to room temperature. Heat a kadai and add the khoya to it. Cook i low flame for few minutes.
Add sugar and mix well. The knoya will become little bit loose and sugar will start to dissolve, now keep cooking in low flame.
Add cocoa powder and mix well. Mix well and cook in low flame till the whole mixture turns into a soft mass.
Transfer the whole mixture into a greased plate. Spread the mixture into desired thickness using a greased rolling pin or greased ziplock cover and allow to set for 10-15 minutes. You may freeze it too. Once set cut into desired shapes. Store chocolate burfi airtight and serve.
Notes
1. Use a deep plate to make thick burfis. 2. You can cook khoya in little ghee if preferred 3. use cardamom or vanilla for flavoring if needed