Sift the flour, baking powder, and salt together, then put them aside for the moment. In a big bowl, cream the margarine and sugar together until it's light and fluffy. Beat in the eggs one at a time, then stir the vanilla in. Gradually blend in the sifted ingredients until they've been fully absorbed. Cover dough, and let it chill for 2 hours.

Turn the oven up to 400 F and grease cookie sheets. On a clean floured surface, roll out small chunks of your dough to 1/4 inch thickness. Use cookie cutters to cut them into some fun shapes.

Bake the cookies for 6 to 8 minutes in the preheated oven, or until edges are just barely brown. Take the cookies out, let them cool on wire racks, then decorate however you like.