Marshroom... or mushmallow?

With all the rains we've had this summer, we've also had plenty of these in our lawn. I couldn't help thinking of a marshmallow when I saw this one:

Here it is from another side. It even looks like it's starting to get a toasted. See that little tan spot on its right?

Below is what it looked like the next day, just before sunset. The little tan spot was raised a bit, just like a toasting marshmallow bubbling up. :)

So whaddya think... marshroom or mushmallow??? ;)

Here's a little different one. Looks more like a button or a bottlecap. Isn't there actually a "button mushroom"? I don't know my mushrooms very well. I'm not very fond of them.

They're now gone. I mowed them off. That first one was a tough little thing and resisted the mower blades quite well. I had to go over it twice!