With the rack in the middle position, preheat the oven to 180 °C (350 °F). Line a baking sheet with parchment paper.
In a large bowl, combine all the dry ingredients. Add the egg, butter and stir with a wooden spoon until smooth.
Place the dough in the centre of the baking sheet. With your hands, shape the dough into a large 23-cm (9-inch) in diameter cookie. Be careful to spread the dough to an even thickness.
Garnish the surface of the cookie according to the taste of each of your family member. Place the baking sheet in the oven and bake for about 15 minutes or until the edge of the cookie is golden brown. Let the cookie cool completely and cut it into wedges.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.