Sugar gives dough its sweetness & is an immediate source of food for the yeast. It also imparts tenderness to the crumb & color to the crust. In large amounts it helps provide essential bulk to a baked good. In small amounts (less than 1/3 cup), sugar can often times be deleted or substituted with any sweetener. However, if removing sugar in a recipe requiring less than 1/3 -1/2 cup sugar, use equal amounts of Ultimate Sweetener to retain essential bulk.  Or as suggested by Andrea Stein, GFCFKids, try substituting unsweetened shredded coconut for most (or all) of the sugar in a recipe.  Enhance the sweetness with some added Stevia or Ki-Sweetä.  And beware when making sugar substitutions.  There are differences when baking with dry and liquid sugars (like honey, liquid fructose, etc).  Some sugar/substitutes, like fructose, require a lower oven heat to prevent burning.  If using liquid substitutes, you will need to account for the added moisture somewhere else in your recipe. Even if tolerated in a recipe, reducing, substituting, or omitting the sugar may result in a loss and/or change in flavor, texture, & color of the final baked good.