In a large mixing bowl beat butter with an electric mixer on medium for 30 seconds. Add sugar, baking powder, and salt.Beat until combined. Beat in egg, milk, and vanilla until combined. Beat in as much of the flour as you can with mixer. Stir in any remaining flour. divide dough in half. Chill half hour.
On lightly floured surface roll half the dough at a time until 1/8 inch thick. Using cookie cutter cut dough into desired shape. Place 1 inch apart on cookie sheet.
Bake at 375 for 7 to 8 min or until edges are firm and bottoms are lightly browned. Cool on wire rack.