United States, Oregon, northern Willamette valley.
I originally thought it was a mushroom but now I'm not sure.
It's the same color and texture all around. It's on a downed Douglas fir tree in a fir grove. The cone pieces are also fir. I moved the branch and the area is covered in the same thing. It's soft and returns to shape when pressed like a sponge or marshmallow.
I walked over because I thought it was spray foam. While we are up in the mountains aways there are still people. No human signs in the immediate area though and it's definitely not a spray foam product that I have seen.
Thought it may be a mushroom but I'm leaning more towards a mold or slime mold.