Don't you hate it when you want to bake with brown sugar but it's hard as a rock? I have a super easy way to soften it in about a minute or two. Here's how:
Break up into smaller chunks with a meat mallet (or hammer, but watch your fingers) and place amount you want to use in a microwave-safe bowl.
Wet and wring out a paper towel and cover the bowl.
Microwave on high for 30 second increments until you can break apart the brown sugar with a fork or spoon. You may need to re-wet the paper towel.
That's it - easy!