Microwave......covered 1/2 power about 30 seconds....then test and maybe give it more time.
Linda C

You can do it in a very low oven, too. 200-250° but watch it carefully.

Thanks so much!! :)

You can buy a sugar stone which a ceramic tile, that you soak in water and then you keep it inside the package of brown sugar. This will keep it from getting hard, but I not sure if it will soften it.

A slice of apple in the bag will soften it, but maybe not soon enough.

Microwaving works, but add an apple slice for extra moisture. Note, use the brown sugar when you remove it from the micro, because it will soon harden again.

I have foung that by buying real brown sugar instead of the molasses flavored stuff they call brown sugar, the problem of hard sugar solves itself. You have to do some label reading, but its much better to buy the real thing. I usually find it under the Domino label. Just keep it in a zip lock bag in the frig.

How about grating it? Might be a lot of work for 1/2 bag but might be able to do part of it if you need it for a recipe.

Lori

I stopped buying brown sugar years ago. I buy regular sugar and add molasses. Also, it is easier to work with.

Putting a fresh slice of bread in the bag will soften it up in a few hours.