Brown sugar is a combination of regular granulated white sugar and molasses and can add more flavor to your recipes than white sugar alone. It naturally contains more moisture than white sugar thanks to its molasses content. But in order to melt, it still needs additional moisture from liquid ingredients, such as butter or water, to partially dissolve the sugar. If you attempt to melt brown sugar alone on the stove, it'll just end up getting scorched. Here's an easy way to melt brown sugar in the microwave.
Place brown sugar into a microwave-safe bowl.
Fill another bowl partially with water to help keep the brown sugar moist. This is especially important if the brown sugar has begun to harden or dry out.
Microwave the bowls of sugar and water for 30 seconds on high.
Remove the bowl of brown sugar from the microwave and stir gently. It should be noticeably softening at this point.
Return the brown sugar to the microwave and heat for another 30 seconds.
Remove the bowl and stir it again.
Continue microwaving the sugar for 30-second intervals, stirring in between, until melted to your satisfaction.