1Heat oven to 350°F. In large bowl, break up cookie dough. Beat in cocoa with electric mixer until well blended.
2On lightly floured surface, roll out half of dough at a time to 1/8-inch thickness. With 2 1/2-inch heart-shaped cookie cutter, cut out heart shapes. On ungreased cookie sheets, place shapes 1/2 inch apart.
3Bake 10 to 12 minutes or until set. Remove cookies from cookie sheets; place on cooling racks. Cool completely, about 5 minutes.
4In small bowl, mix frosting and peppermint extract until well blended. Spread about 2 teaspoons frosting on each cookie. Sprinkle each with about 1/4 teaspoon crushed candy.