In a large bowl, cream together the shortening and white sugar until smooth. Beat in the eggs one at a time, then stir in the milk and 1 teaspoon vanilla. Combine the flour, baking powder, and salt; stir into the creamed mixture. Cover dough, and chill for at least one hour.
Preheat the oven to 400 degrees F (200 degrees C). Lightly grease cookie sheets, or line with parchment paper. On a lightly floured surface, roll out the dough to 1/4 inch in thickness. Cut into desired shapes with cookie cutters. Place cookies 1 1/2 inches apart onto cookie sheets.
Bake for 6 to 8 minutes in the preheated oven. Remove cookies from baking sheets to cool on wire racks. Cool completely before frosting.
In a small bowl, beat the butter, 1 teaspoon vanilla and confectioners' sugar until smooth. Mix in the milk one tablespoon at a time until a good spreading consistency is reached. Stir in food coloring to desired shade. Decorate cooled cookies, and set on waxed paper to harden.
