In a large mixing bowl, using a hand mixer on medium speed, combine 1 cup butter, ½ cup powdered sugar and ½ teaspoon peppermint extract until creamy.

In a medium mixing bowl, mix together flour and cornstarch. Gradually add flour mixture to butter mixture until well combined.

Cover bowl with plastic wrap and refrigerate 60 minutes.

Preheat oven to 350 degrees F.

Remove cookie dough from fridge and using a 1 teaspoon sized cookie scoop, scoop dough and shape into dough balls.

Place dough balls 2 inches apart onto ungreased cookie sheets and sprinkle with crushed peppermint candies.

Bake cookies for 13 minutes until edges are lightly browned.

Remove cookies from oven Let stand 1 minute (important!); remove from cookie sheets. Cool completely.

Combine 1-½ cups powdered sugar, 2 tablespoons butter, ¼ teaspoon peppermint extract, red food coloring (if using), and enough milk for desired glazing consistency in small bowl. Stir in food color. Drizzle over cooled cookies and immediately sprinkle with crushed candy.