The many differences between cookie- and cracker-baking are discussed and described in terms of the functionality, and functional requirements, of the major biscuit ingredients--flour and sugar. Both types of products are similar in their major ingredients, but different in their formulas and processes. One of the most important and consequential differences between traditional cracker and cookie formulas is sugar (i.e., sucrose) concentration: usually lower than 30% in a typical cracker formula and higher than 30% in a typical cookie formula. Gluten development is facilitated in lower-sugar cracker doughs during mixing and sheeting; this is a critical factor linked to baked-cracker quality. Therefore, soft wheat flours with greater gluten quality and strength are typically preferred for cracker production. In contrast, the concentrated aqueous sugar solutions existing in high-sugar cookie doughs generally act as an antiplasticizer, compared with water alone, so gluten development during dough mixing and starch gelatinization/pasting during baking are delayed or prevented in most cookie systems. Traditional cookies and crackers are low-moisture baked goods, which are desirably made from flours with low water absorption [low water-holding capacity (WHC)], and low levels of damaged starch and water-soluble pentosans (i.e., water-accessible arabinoxylans). Rheological (e.g., alveography) and baking tests are often used to evaluate flour quality for baked-goods applications, but the solvent retention capacity (SRC) method (AACC 56-11) is a better diagnostic tool for predicting the functional contribution of each individual flour functional component, as well as the overall functionality of flours for cookie- and/or cracker-baking.