Whisk together flour, baking powder, and salt in a medium bowl. Set aside.
Using stand mixer, cream together butter and brown sugar until fluffy. Mix in egg and vanilla extract.
Add flour in two batches, mixing just until combined.
Divide dough into two, then shape each half into a ball. Flatten each ball into a disk about 1-inch thick, then cover with plastic wrap. Chill for at least 2 hours (or overnight). Place cookie stamps in refrigerator, too.
Once dough has chilled, preheat oven to 375 degrees. Line two baking sheets with parchment paper. Add granulated sugar to a small bowl.
Roll a piece of dough into a golf ball-sized ball, then roll in granulated sugar. Place on baking sheet.
Dip cookie stamp into sugar, then press ball until dough reaches edges of stamp. Repeat with remaining dough.
Once you have filled a baking sheet, freeze cookies for 10 minutes.
Bake chilled cookies until golden brown on bottom, about 9 to 10 minutes.
Let cookies cool on baking sheet for 5 minutes, then transfer to a baking rack to cool completely before decorating. Enjoy!
Prepare Icing (Optional):
Whisk together powdered sugar, milk, and vanilla until smooth. Add just enough milk to make a thin glaze (should be fairly runny).
Dip cooled cookies in glaze, then brush off excess. Or brush glaze on cookies using a decorating brush. Place cookies on a parchment lined tray until glaze is set.
Read info before recipe for tons of extra tips and tricks, more cookies decorating ideas, and other cookie dough recipes.If you'd prefer not to roll cookies and stamps in sugar, you may dip the stamps in flour or brush them lightly with oil (or spray with nonstick spray) instead.For best results, bake one sheet of cookies at a time.