Hugs and kisses sugar cookies

1. In a large bowl, cream the butter and sugar until fluffy. Add the egg and beat well, then mix in the vanilla. In a separate bowl, combine the flour, baking soda and cream of tartar. Add the flour mixture to the butter mixture, one third at a time, until thoroughly combined. Divide the dough into 2 equal portions and flatten each in a disk. Cover each disk in plastic wrap and refrigerate for 2 to 3 hours, or until the dough is firm enough to work with. If it becomes too firm, soften at room temperature for about 5 minutes. Preheat the oven to 350. On a floured surface, roll out dough to a 1/4 inch thickness. Then use floured cookie cutters to cut out desired shapes Using a metal spatula, carefully transfer the cookies to a baking sheet, leaving about 2 inches between them. Bake for 8 to 10 minutes or until lightly browned around the edges. Remove the cookie sheets from the oven, place on wire racks and cool for 2 to 3 minutes. Using a metal spatula, transfer the cookies to the rack and cool completely. While the cookies are cooling, make the buttercream icing: Beat together the sugar, butter and vanilla. Add the milk a few drops at a time until the mixture is spreadable. Frost the cookies with the icing and sprinkle on tinted red or green sugar.