Heat oven to 350°F. In large bowl, break up cookie dough. Stir or knead in 1/4 cup flour until well blended. Remove half the dough, and refrigerate remaining dough until needed.
Sprinkle 2 tablespoons flour onto work surface. With rolling pin, roll dough 1/8 inch thick. With floured 3-inch heart-shaped cookie cutter, cut out dough hearts. Gently brush excess flour from dough hearts. On ungreased cookie sheets, place hearts 2 inches apart. Repeat with remaining dough and 2 tablespoons flour.
Bake 7 to 9 minutes or until light golden brown. Cool 1 minute; remove from cookie sheets to cooling racks. Cool completely, about 15 minutes.
Place sheet of waxed paper on cookie sheet. In 1-quart saucepan, melt chocolate chips and shortening over low heat, stirring occasionally, until smooth. Remove from heat. Dip half of each cookie into melted chocolate; allow excess to drip off. Place on waxed paper. Refrigerate until set.