Perhaps not quite as fat as you are looking for but this guy discusses a few 26x2.3 folding tires.
I used an earlier version of that Michelin Pilot over a few years and over 2500 miles or so and was pleased with how they rode and and held up.
They're not too heavy at around 650g I think he said.
Also he mentions a Maxxis DTH folding tire in a 26x2.3.
I've ridden that DTH tire in a 26x2.15 and have also like it quite a bit.
The ones I tried were not quite a Rat Trap Pass but not all that far behind in my view and for my purposes proving to be more flat resistant for my urban riding.
Good riding
Paul in Dallas