can I use for cooking.

Most supermarkets should have a suitable option - just check labels for 100% cocoa and no other ingredients.

BTW in my interpretation of the rules of induction (assuming you are on induction and not halfway up the OWL ladder) cocoa is only allowed as a spice and so in very small amounts fractions of a teaspoon, as you would for other spices).

To use larger amounts like a tablespoon or more per serving which some recipes call for I would think you would need to be at the nuts/seeds rung of OWL.

Thanks.

I'm OWL

If you have an Aldi near you, check out their cocoa, I think it's the best you can buy. Tastes far better than even the Green & Black or Cadbury one.