Running out of brown sugar mid-recipe is a common kitchen problem, but it can be solved without a trip to the store. According to the source material, combining granulated sugar with molasses produces brown sugar, with different ratios for light and dark varieties.
For one cup of light brown sugar, mix 1 cup granulated sugar with 1 1/2 tablespoons molasses. For one cup of dark brown sugar, use 1 cup granulated sugar with 1/4 cup molasses. A food processor works well for blending the two ingredients, the source notes, though it is not required.
The method relies on two shelf-stable pantry items, making it useful when a recipe calls for brown sugar and only white sugar is on hand. The source does not specify whether other appliances, such as a fork or whisk, would achieve the same result, nor does it address storage or shelf life of the homemade version.
The original article concludes with an encouraging note: "Now bring on those brown sugar shorties!" 
Editorial Notes