Functional cookie for coeliacs from teff flour that is free of hydrocolloids, starches and added fats, whose formulation comprises the following ingredients, according to proportions by weight based on the initial amount of teff flour: skimmed milk, 92-96% ; plain yogurt, 26-30%; brown sugar, 12-16%; defatted cocoa powder, 2-5%; orange zest, 6-10%, and crushed hazelnuts, 15-20%, and a process for preparing said functional biscuit comprising the following steps: mixing of ingredients and kneading, resting, rolling, die-cutting and baking. (Machine-translation by Google Translate, not legally binding)