To make cookie dough, mix flour, baking powder, salted butter, sugar, egg, vanilla extract, and milk. To make them into shapes, roll out cookie dough onto a lightly floured surface and use cookie cutters to make whatever shapes you like. For this recipe, you just need round ones. Then, cook on ungreased cookie sheets (using cooking spray is fine too) in an oven preheated to 350 degrees F for 8 to 10 minutes or until they are light golden. Let them cool on a cooling rack for 30 minutes before decorating.