In a bowl, combine the flour, baking powder, and salt. Set aside.
In another bowl, beat the eggs with the sugar and vanilla until light and fluffy. Stir in the butter and dry ingredients until the batter is smooth. Shape into a disc with your hands and cover with plastic wrap. Refrigerate for at least 1 hour.
With the rack in the middle position, preheat the oven to 190 °C (375 °F). Line two baking sheets with parchment paper.
In a bowl, combine the egg yolk and milk. Set aside.
On a floured work surface, roll out the dough to about ½-cm (¼-inch) thick. With a 7.5-cm (3-inch) fluted cookie cutter, cut about 20 cookies, reusing scraps. Brush with the egg wash. If desired, sprinkle with coarse sugar crystals.
Bake for about 13 minutes or until the cookies are golden brown. Let cool.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.