If I'm following you correctly, you are saying that the conclusion of Chalmers' parody is actually correct, as having a recipe is indeed not sufficient to successfully bake a cake: you will not succeed without the ingredients, for example.

This is indeed true, but we should bear in mind that Chalmers' parody is just that: a parody, not a rigorous argument. It seems clear that, if Chalmers wanted to make it more rigorous, he would have concluded with something like "therefore, even if you have all the prerequisites for baking a cake (ingredients, tools, familiarity with basic cooking operations...), no recipe is sufficient to instruct you in successfully completing the task." This would be a better argument, but a flabbier, less to-the-point parody, and it is reasonable for Chalmers to leave it to his readers to get his point.