Chocolate Peppermint Shortbread Cookies

Cookies:
3/4 cup butter (1 1/2 sticks) butter, softened
1/2 cup powdered sugar
1/4 teaspoon pure peppermint extract
2 (1-ounce) squares unsweetened chocolate, melted, cooled slightly
1 1/2 cups all-purpose flour
1 cup semi-sweet mini chocolate chips
Frosting:
1 cup powdered sugar
2 tablespoons butter, softened
1 tablespoon milk
1/4 teaspoon pure peppermint extract
1 drop green food coloring
Drizzle:
1/2 cup semi-sweet mini chocolate chips
1/2 teaspoon vegetable shortening

Heat oven to 375 degrees. Combine all cookie ingredients except flour and mini chocolate chips in large mixer bowl. Beat at medium speed until creamy (1 to 2 minutes). Reduce speed to low. Add flour; continue beating until mixture forms a dough (1 to 2 minutes). Stir in 1 cup mini chocolate chips.
Roll dough into 1-inch balls. Place 2 inches apart on ungreased shiny cookie sheet. Flatten to 1 1/2 -inch circle with bottom of glass dipped in flour. Bake for 5 to 7 minutes or until set. Do not overbake. Let stand 2 minutes; remove from cookie sheet. Cool completely on wire rack.
In small mixer bowl combine all frosting ingredients. Beat at low speed until smooth. Add additional milk (1 teaspoon at a time) if frosting is too thick.
Frost cooled cookies with frosting. Place on waxed paper to drizzle.In small microwave safe bowl, combine 1/2 cup mini chocolate chips and shortening. Microwave on high, 1 to 1/2 minutes, stirring every 30 seconds, until smooth. With teaspoon drizzle thin lines over frosting. Let stand until chocolate is set (at least 30 minutes).

Submitted by Grace