These are Giant Puffball Mushroom (Calvatia gigantean). The meat of giant puffballs tastes very similar to tofu or melted cheese when cooked. To prepare, remove any brown portions and tough skin, which sometimes peels off easily. Do not soak in anything. Puffballs may be sauteed, broiled, or breaded and fried; they do not dehydrate well, but may be cooked and then frozen.
Video by Thomas Harwood