• Cookies:
• In the bowl of a stand mixer, cream butter and sugar together until fluffy. Add egg and beat on medium speed until incorporated. Add in vanilla.
• In a bowl combine flour, cornstarch and baking soda, then add to the sugar-butter mixture. Mix until incorporated.
• Wrap dough in plastic wrap and refrigerate for 2 hours or overnight.
• Roll out dough about 1/4 inch thick. Cut out Christmas tree shaped cookies using a cookie cutter.
• Chill cookies for at least 30 minutes.
• Preheat oven to 350 F (177 C). Line baking sheets with parchment paper.
• Bake cookies for 10-13 minutes until they start to turn golden. Be careful not to over bake.
• Transfer cookies to a cooling rack and let them cool completely.

Chocolate ganache:

• Bring heavy cream to just a boil and remove from heat. Place chocolate chips in a medium bowl. Pour cream over chocolate chips, stirring to combine (might take a few minutes). Add in peppermint extract (if you decide to use it). Set ganache a side to set, stirring every so often.

To assemble the the cookies:

• Once cookies have cooled to room temperature, fill them with the ganache , you can use a piping bag or spatula. Then dip them in an angle into the ganache. Top with sprinkles.