Heat over to 400ºF. Combine sugar, 1 cup butter/margarine, egg, and vanilla in a large mixing bowl. Beat at medium speed until light and fluffy. Add baking powder, flour, salt, and then beat at low speed until a soft dough forms. Sprinkle flour on counter top. Roll the dough out to about 1/8" thick. Cut dough with cookie cutter (that has been dipped in flour). Place hearts 2" apart on ungreased cookie sheets. Bake for 9 - 12 minutes, or until cookie edges are golden brown. Set the cookies aside cool down. In a small saucepan over low heat, melt hot rock candies and 1 tablespoon butter/margarine, stirring the mixture until smooth. Dip half of each cooled down cookie into the melted candy, allowing excess to drip off. Place cookies on a cookie sheet lined with waxed paper. Refrigerate until set. Add a handwritten love poem, a rose, and voila! You are all set to put cupid out of business! Yields: 3 - 4 dozen cookies!