• Preheat the oven to 400 ° F

Make the chocolate ganache.

• Place the chocolate in a medium bowl.
  8 ounces semi-sweet chocolate chips
• Heat the heavy cream in a small saucepan over medium heat until hot but DO NOT let it boil. Then remove from heat and pour over chocolate chips.
  1 cup heavy cream
• Let it sit for 3 minutes and the stir with a spatula until blended.
• Place in the refrigerator to set and firm for about 30 minutes.
• You will remove the ganache from the refrigerator and let it sit and become a spreadable consistency while you make the cookies.

Make the cookies

• For even cookie sizes: On a piece of parchment paper that is cut to fit a large baking sheet, draw 10 two ½ inch lines on the parchment paper spacing them 3 inches apart to account for the cookies spreading. This is optional if you'd like. You can just eyeball it too.
• Turn the parchment over and place it on the baking sheet.
• In a medium bowl, add the flour, cornstarch, baking soda and salt and whisk together.
  2 cups all purpose flour, 1 tablespoon corn starch, 1 teaspoon baking soda, ½ teaspoon salt
• In the large mixing bowl, add the softened butter, powdered sugar and granulated sugar and blend together until fluffy. (You can also use bowl of a stand mixer)
  ½ cup unsalted butter, ½ cup powdered sugar, ⅓ cup granulated sugar
• Add in the egg, vanilla extract and milk.
  1 egg, 2 teaspoons vanilla extract, 1 tablespoon whole milk
• Lastly add in the dry ingredients and mix well until there are no dry flour spots.
• Using a ruler, cut 1 ½ inches off the tip of a piping bag or large plastic zip closure baggie.
• Place the bag in a tall cup and spoon the dough inside of it being careful not to over fill the bag.
• Twist the top closed and pipe lines of cookie dough along the lines you made on the parchment
• Press the dough down slightly.
• Place in the preheated oven and bake for 10-12 minutes.
• After baking, transfer the cookies to a wire cooling rack for at least 10 minutes.

Assemble the cookies

• Spread the ganache onto the flat side of a cookie and top with another cookie to make a sandwich cooking.