Combine ingredients in a stand mixer fitted with a paddle attachment.
1 cup sugar, 2.5 tsp molasses
Mix on low for two minutes, scrape the sides, and mix for another two minutes.
Transfer to an air-tight container and store just as you would normal brown sugar.
Notes
The recipe above is for medium brown sugar. Light brown sugar - 1 cup of sugar to 2 1/2 tsp of molassesDark brown sugar - 1 cup of sugar to 1 1/2 tbsp of molassesYou can also mix by hand with a fork, but be prepared for some amazing arm muscles by the end of it!