Preheat oven to 400°F.

In a large bowl with a mixer, cream together butter and powdered sugar. Mix in egg and vanilla. Blend in flour, baking powder, and salt. Mix until the dough forms a ball.

Roll out on a floured surface and cut with cookie cutter; use smaller cookie cutter to make the stained-glass cut out. Place on parchment lined baking sheet. Fill cut-out with crushed hard candy.

Bake at 400° for 7–9 minutes, until cookies are golden but tops are not browned yet. Cool completely on sheet pan before removing.