Combine the sugar and the desired amount of molasses in a mixing bowl or food processor. Process according to the times below depending on what type of machine you are using.
A food processor will get the job done in about 1 minute. You may need to stop and scrape the sides of the bowl down once.
A stand mixer will get the job done in about 3- 5 minutes. About halfway through stop the mixer, scrape down the sides, and break up any big molasses clumps with a fork.
A hand mixer will take anywhere from 5-8 minutes; possibly longer. You will need to stop quite a few times to break up big molasses lumps with a fork.
Store it in the refrigerator or a cool, dark place in a plastic bag with all of the air squeezed out of it.