Monogrammed favors are wedding classics -- here they're iced onto cookies, making a versatile treat.
Sift together flour, baking powder, and salt into a large bowl; set aside.
Put butter and sugar in the bowl of an electric mixer. Mix on medium speed until pale and fluffy, about 3 minutes. Mix in eggs and vanilla. Reduce speed to low; gradually mix in flour mixture. Divide dough in half; wrap each half in plastic. Refrigerate 1 hour (or up to 2 days).
Preheat oven to 350 degrees. Transfer dough to a lightly floured surface. Roll out to 1/4 inch thick. Cut out shapes with 3-inch cookie cutters. Space 1 inch apart on parchment-lined baking sheets. Repeat with remaining scraps of dough. Refrigerate 15 minutes.
Bake until set, 12 to 14 minutes. Let cool on sheets on wire racks.