Mix powdered sugar, cream cheese, and milk until smooth. Stir in peppermint candy, then set aside.
Prepare Dough:
Cream together butter and powdered sugar until well mixed using a stand mixer. Mix in egg yolks and extract.
Add flour and salt to butter mixture. Mix on low speed until flour is mostly incorporated, then turn up speed for a few seconds until dough comes together.
Scoop out generous teaspoon of dough. Roll dough into a ball and place on an ungreased baking sheet. Press thumb into dough to make indentation.
Repeat process with remaining dough, placing cookies 1-inch apart on baking sheet.
Fill indentation with ¼ teaspoon candy cane filling.
Bake cookies for about 10 to 12 minutes, or until filling puffs up slightly and cookie bottoms are light brown.
Cool cookies for a couple minutes on baking sheet, then transfer to a wire rack to cool completely.
Add Topping:
Microwave chocolate chips in a small bowl at 10 second intervals, stirring very well between each interval, until melted.
Stir in peppermint extract, then transfer chocolate to a piping bag with a small round tip. Drizzle chocolate over cookies.
Let chocolate harden before serving cookies. Enjoy!
Notes
I used crushed candy canes for the cookie filling, but any kind of peppermint candy will work.You should be able to fit 24 cookies on one average-size baking sheet (4 rows of 6 cookies). Bake the cookies in batches, one cookie sheet at a time.White chocolate melts quickly. Don't overheat it or it will seize up! To avoid problems, make sure to microwave the chocolate in short, 10-second intervals. And keep in mind that there should still be some chocolate chips visible after microwaving ... they will continue to melt as you stir the chocolate.Instead of a piping bag, you may use a decorating bulb (my fave decorating tool!) or a zip top plastic bag with the corner snipped off.Check out the info before this recipe card for more tips, related recipes, and more!