Which part of the brain deals with thinking?

The brain is a remarkable and complex structure responsible for thinking skills. Several parts of the brain work together in a sophisticated manner to integrate information and develop thoughts. The term thinking skills refers to a wide range of processes, including consciously remembering facts and information, solving concrete or abstract problems using known information, and incorporating reasoning, insight or ingenuity.

The cerebrum deals with the part of the brain that thinks. if you have more questions, let me know

That would be a working theory.