Very basic baking ingredients would be flour and water. Add a bit of salt, and you can have a tasty flat bread or cracker. The next basic ingredient would be some sort of fat, whether lard (animal...
flour (if you use self raising flour DO NOT use baking powder or soda), butter, sugar, eggs, baking powder or soda (if you use self raising flour DO NOT use baking powder or soda), and an oven.