In large bowl, whisk flour, baking powder, and salt. With an electric mixer, cream butter and sugar until light and fluffy. Beat in egg and vanilla. With mixer on low, gradually add flour mixture; beat until combined. Divide dough in half; flatten into disks. Wrap each in plastic; freeze until firm, at least 20 minutes, or place in a resealable plastic bag, and freeze up to 3 months (thaw in refrigerator overnight).

Preheat oven to 325 degrees. Line baking sheets with parchment. Remove one dough disk; let stand 5 to 10 minutes. Roll out 1/8 inch thick between two sheets of floured parchment, dusting dough with flour as needed. Cut shapes with cookie cutters. Using a spatula, transfer to prepared baking sheets. (If dough gets soft, chill 10 minutes.) Reroll scraps; cut shapes. Repeat with remaining dough.

Bake, rotating halfway through, until edges are golden, 10 to 18 minutes (depending on size). Cool completely on wire racks. To ice cookies, spread with the back of a spoon. Let the icing harden, about 20 minutes. Decorate as desired

To make this classic cookie, outline and flood it with thin, orange icing. Allow it to dry completely. Using thicker, white icing, pipe around the edge of the cookie and add details including feathers, wings, an eye, and a chest feathers. Flock the icing with sanding sugar while wet. Once dry, tap off excess sanding sugar and add yellow dots to the tail feathers with thick icing.